Docs: Additional updates to build environment instructions
1. Add configuration instructions for ccache on Mac OS.
2. Move ccache instructions to new section, since setup applies to build environments on both Linux and Mac OS.
3. Make Mac OS references consistent.
4. Format branch tags, system paths and commands with <code> tag.

Change-Id: If5ae69c4de09542d5539882a10d84892d9e7d816
Signed-off-by: Collin El-Hossari <ceh@google.com>
diff --git a/src/source/building-running.jd b/src/source/building-running.jd
index ed8c4b7..239ebe6 100644
--- a/src/source/building-running.jd
+++ b/src/source/building-running.jd
@@ -24,14 +24,14 @@
   </div>
 </div>
 
-The following instructions to build the Android source tree apply to all branches, including master. 
+The following instructions to build the Android source tree apply to all branches, including <code>master</code>.
 
 <h2 id="choosing-a-branch">Choosing a Branch</h2>
 <p>Some of the requirements for your build environment are determined by which
 version of the source code you plan to compile. See
 <a href="build-numbers.html">Codenames, Tags, and Build Numbers</a> for a full listing of branches you may
 choose from. You may also choose to download and build the latest source code
-(called "master"), in which case you will simply omit the branch specification
+(called <code>master</code>), in which case you will simply omit the branch specification
 when you initialize the repository.</p>
 <p>Once you have selected a branch, follow the appropriate instructions below to
 set up your build environment.</p>
@@ -40,7 +40,7 @@
 <p>The basic sequence of build commands is as follows:</p>
 <h2 id="initialize">Initialize</h2>
 <p>Initialize the environment with the <code>envsetup.sh</code> script. Note
-that replacing "source" with a single dot saves a few characters,
+that replacing <code>source</code> with <code>.</code> (a single dot) saves a few characters,
 and the short form is more commonly used in documentation.</p>
 <pre><code>$ source build/envsetup.sh
 </code></pre>
@@ -49,12 +49,12 @@
 </code></pre>
 <h2 id="choose-a-target">Choose a Target</h2>
 <p>Choose which target to build with <code>lunch</code>.  The exact configuration can be passed as
-an argument, e.g. </p>
+an argument. For example, the following command:</p>
 <pre><code>$ lunch aosp_arm-eng
 </code></pre>
-<p>The example above refers to a complete build for the emulator, with all debugging enabled.</p>
+<p>refers to a complete build for the emulator, with all debugging enabled.</p>
 <p>If run with no arguments <code>lunch</code> will prompt you to choose a target from the menu. </p>
-<p>All build targets take the form BUILD-BUILDTYPE, where the BUILD is a codename
+<p>All build targets take the form <code>BUILD-BUILDTYPE</code>, where the <code>BUILD</code> is a codename
 referring to the particular feature combination. Here's a partial list:</p>
 <table>
 <thead>
@@ -111,7 +111,7 @@
 <p>Build everything with <code>make</code>. GNU make can handle parallel
 tasks with a <code>-jN</code> argument, and it's common to use a number of
 tasks N that's between 1 and 2 times the number of hardware
-threads on the computer being used for the build. E.g. on a
+threads on the computer being used for the build. For example, on a
 dual-E5520 machine (2 CPUs, 4 cores per CPU, 2 threads per core),
 the fastest builds are made with commands between <code>make -j16</code> and
 <code>make -j32</code>.</p>
@@ -126,7 +126,7 @@
 <p>Once the device is in fastboot mode, run </p>
 <pre><code>$ fastboot flashall -w
 </code></pre>
-<p>The <code>-w</code> option wipes the <code>/data</code> partition on the device; this is useful for your first time flashing a particular device, but is otherwise unnecessary.</p>
+<p>The <code>-w</code> option wipes the <code>/data</code> partition on the device; this is useful for your first time flashing a particular device but is otherwise unnecessary.</p>
 <p>For more information about building for and running on actual hardware, see
 <a href="building-devices.html">Building for Devices.</a></p>
 <h3 id="emulate-an-android-device">Emulate an Android Device</h3>
@@ -141,10 +141,10 @@
 $ prebuilts/misc/linux-x86/ccache/ccache -M 50G
 </code></pre>
 <p>The suggested cache size is 50-100G.</p>
-<p>You can watch ccache being used by doing the following:</p>
+<p>On Linux, you can watch ccache being used by doing the following:</p>
 <pre><code>$ watch -n1 -d prebuilts/misc/linux-x86/ccache/ccache -s
 </code></pre>
-<p>On OSX, you should replace <code>linux-x86</code> with <code>darwin-x86</code>.</p>
+<p>On Mac OS, you should replace <code>linux-x86</code> with <code>darwin-x86</code>.</p>
 <p>When using Ice Cream Sandwich (4.0.x) or older, you should replace
 <code>prebuilts/misc</code> with <code>prebuilt</code>.</p>
 <h2 id="troubleshooting-common-build-errors">Troubleshooting Common Build Errors</h2>
@@ -176,7 +176,7 @@
 <pre><code>$ apt-get install python
 </code></pre>
 <h3 id="case-insensitive-filesystem">Case Insensitive Filesystem</h3>
-<p>If you are building on an HFS filesystem on Mac OS X, you may encounter an error such as</p>
+<p>If you are building on an HFS filesystem on Mac OS, you may encounter an error such as</p>
 <pre><code>************************************************************
 You are building on a case-insensitive filesystem.
 Please move your source tree to a case-sensitive filesystem.