Build Skia as a static library

- Roll GYP so that we get non-thin archives on Linux
- Add merge_static_libs.py
- Add skia_core_lib target which builds core, ports, opts*, and utils
- Replace dependencies on core/ports/opts/utils with skia_core_libs
- Rename exportable libraries with "skia_"
Review URL: https://codereview.appspot.com/6619049

git-svn-id: http://skia.googlecode.com/svn/trunk@5889 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/xml.gyp b/gyp/xml.gyp
index b7878e2..b7fdb83 100644
--- a/gyp/xml.gyp
+++ b/gyp/xml.gyp
@@ -2,7 +2,9 @@
   'targets': [
     {
       'target_name': 'xml',
+      'product_name': 'skia_xml',
       'type': 'static_library',
+      'standalone_static_library': 1,
       'include_dirs': [
         '../include/config',
         '../include/core',