liblog: enable logging to logd.

* Modify liblog to send all messages to the new syslog user
  space daemon.

Original-Change-Id: I0ce439738cd921efb2db4c1d6a289a96bdbc8bc2
Original-Change-Id: If4eb0d09409f7e9be3eb4bb7017073dc7e931ab4
Signed-off-by: Nick Kralevich <nnk@google.com>

* Add a TARGET_USES_LOGD make flag for BoardConfig.mk to manage
  whether logd is enabled for use or not.
* rename syslog to logd to avert confusion with bionic syslog
* Add fake log support back in
* prefilter for logging messages from logd
* Fill in timestamps at logging source
* update abstract log reader
* switch from using suffix for id to v3 format
* log a message when creating devices that a deprecated interface
  is being utilized.

Signed-off-by: Mark Salyzyn <salyzyn@google.com>

(cherry pick from commit 099e2c1f6f706a8600c1cef74cce9066fc315480)

Change-Id: I47929a5432977a1d7235267a435cec0a7d6bd440
diff --git a/liblog/Android.mk b/liblog/Android.mk
index 0d6c970..174ca55 100644
--- a/liblog/Android.mk
+++ b/liblog/Android.mk
@@ -16,7 +16,11 @@
 LOCAL_PATH := $(my-dir)
 include $(CLEAR_VARS)
 
+ifeq ($(TARGET_USES_LOGD),true)
 liblog_sources := logd_write.c
+else
+liblog_sources := logd_write_kern.c
+endif
 
 # some files must not be compiled when building against Mingw
 # they correspond to features not used by our host development tools
@@ -42,7 +46,11 @@
 endif
 
 liblog_host_sources := $(liblog_sources) fake_log_device.c
+ifeq ($(TARGET_USES_LOGD),true)
 liblog_target_sources = $(liblog_sources) log_read.c
+else
+liblog_target_sources = $(liblog_sources) log_read_kern.c
+endif
 
 # Shared and static library for host
 # ========================================================