ManifestXml: add include support

Having the ability to include other manifests is a very practical feature
to ease the managment of manifest. It allows to divide a manifest into separate
files, and create different environment depending  on what we want to release

You can have unlimited recursion of include, the manifest configs will simply be concatenated
as if it was in a single file.

command "repo manifest" will create a single manifest, and not recreate the manifest hierarchy

for example:
Our developement manifest will look like:

<?xml version='1.0' encoding='UTF-8'?>
<manifest>
  <default revision="platform/android/main" remote="intel"/>
  <include name="server.xml"/> <!-- The Server configuration -->
  <include name="aosp.xml" />  <!-- All the AOSP projects -->
  <include name="bsp.xml" />   <!-- The BSP projects that we release in source form -->
  <include name="bsp-priv.xml" /> <!-- The source of the BSP projects we release in binary form -->
</manifest>

Our release manifest will look like:

<?xml version='1.0' encoding='UTF-8'?>
<manifest>
  <default revision="platform/android/release-ext" remote="intel"/>
  <include name="server.xml"/> <!-- The Server configuration -->
  <include name="aosp.xml" />  <!-- All the AOSP projects -->
  <include name="bsp.xml" />   <!-- The BSP projects that we release in source form -->
  <include name="bsp-ext.xml" /> <!-- The PREBUILT version of the BSP projects we release in binary form -->
</manifest>

And it is also easy to create and maintain feature branch with a manifest that looks like:

<?xml version='1.0' encoding='UTF-8'?>
<manifest>
  <default revision="feature_branch_foobar" remote="intel"/>
  <include name="server.xml"/> <!-- The Server configuration -->
  <include name="aosp.xml" />  <!-- All the AOSP projects -->
  <include name="bsp.xml" />   <!-- The BSP projects that we release in source form -->
  <include name="bsp-priv.xml" /> <!-- The source of the BSP projects we release in binary form -->
</manifest>

Signed-off-by: Brian Harring <brian.harring@intel.com>
Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Change-Id: I833a30d303039e485888768e6b81561b7665e89d
2 files changed