The pull request targets:
1) Introduces Gradle support
2) Updates maven support (even thou the apk generated is not
stable)
3) Updates the setup_env.* scripts to support different building
tools
4) Removes non UTF-8 characters
5) Removes switches on R.id entries (not supported anymore from
ADT >= 14)
6) Introduced a binary dependency (.aar) that replace the actionbarsherlock
sub-module
Remainders:
1) Change the sub-module back to the owncloud android library
once the PR will be merge
