make it possible to reference a branch of a local git repository

Reasoning on why this change is wanted can be found
on the "sbt-dev" mailing list,
topic "problem with referencing a local git repository"
minor change: code style
Fix AutoPlugins declared at top-level

Fixes exception occuring when loading auto plugins, which are declared
as top-level classes
Message and since parameters in @deprecated properly placed
Typo fixes + removing unnecessary semicolons
Merge pull request #1423 from lpiepiora/fix-top-level-auto-plugins

Fix AutoPlugins declared at top-level
Merge pull request #1425 from jaceklaskowski/typo-fixes

Typo fixes + removing unnecessary semicolons
Merge pull request #1424 from jaceklaskowski/deprecated-annotation-param-positions

Message and since parameters in @deprecated properly placed
Merge pull request #1409 from vn971/0.13

make it possible to reference a branch of a local git repository