timob-13628: added zOrderOnTop support
Merge branch 'master' of https://github.com/appcelerator-modules/ti.map into timob-13628

Conflicts:
	android/dist/ti.map-android-2.1.2.zip
Merge branch 'master' of https://github.com/appcelerator-modules/ti.map into timob-13628

Conflicts:
	android/dist/ti.map-android-2.1.3.zip
timob-13628: updated docs.
timob-13628: addressed comments
Merge branch 'master' of https://github.com/appcelerator-modules/ti.map into timob-13628

Conflicts:
	android/dist/ti.map-android-2.1.3.zip
	android/documentation/changelog.md
Merge pull request #4 from hieupham007/timob-13628

timob-13628: added zOrderOnTop support