Repository local storage improvements.

Changes:
* removed way too much java.io.File exists/mkdir/isXXX invocations
* relocated mkdir from core to FS LS (of repo baseDir)
* relocated when mkdir happens (only once, not per every getBaseDir invocation)
* repoBase dir is calculated and created only once, and is cached and reused
* improved/removed code duplication regarding storage contexts
Fixed Mocks in UTs
Reformat, no code change
Fixing logging, use slf4j api
Merge remote-tracking branch 'origin/master' into repo-storage-mkdir
Removed deprecated method and casting cleanup.
Removed deprecated methods.

They were deprecated since 2.1 and 2.2
Not using external locking, but syncing on the context itself.

Which is even more correct, as all mutating methods of the context
as synced also.
Merge pull request #216 from sonatype/repo-storage-mkdir

Repository local storage improvements.