Add support to read RepositoryMap from plugin dependencies.

[haroon-sheikh]

E.g. checkstyle plugin currently allows you to read checkstyle config xml from plugin repositories.
https://www.youtube.com/watch?v=XlNbDVOzsYw

[Ardesco]

@rultor release, tag is 1.0.13

[rultor]

@rultor release, tag is 1.0.13

@Ardesco OK, I will release it now. Please check the progress here

[rultor]

@rultor release, tag is 1.0.13

@Ardesco Done! FYI, the full log is here (took me 5min)