Bringing in NPE bug fix
Merge pull request #722 from bhariharan/master

Mobile SDK 2.3.1 Patch Release
Merge branch 'master' into unstable
Latest shared repo commit
Latest shared
Merge pull request #723 from bhariharan/unstable

Merge branch 'master' into unstable
Adding sync down after sync up in sample app
Merge pull request #724 from bhariharan/unstable

Adding sync down after sync up in sample app
Remove SyncBasicHttpParams from httpcore
Fixing test
Merge pull request #725 from bhariharan/unstable

Remove SyncBasicHttpParams from httpcore
Reverting test fix
More path fixes, making ANDROID_HOME prereq
Specifically targeting 'android' tool from the Android SDK
Adding Windows android path, reverting plugin path
Don't need volatile_unstable plugin.

Android doesn't use binaries in the plugin.  The main unstable branch will suffice.