[NEXUS-6680] Yum metadata full rebuild

That nukes complete cache folder and task field
rename.
Add dependency to org.bouncycastle:bcprov-jdk15on needed by ldap test suite
Merge pull request #796 from sonatype/nexus-2.11.x-NEXUS-6680-full-rebuild

[2.11.x][NEXUS-6680] Yum metadata full rebuild
workaround case where the default encoding is not utf-8 - https://github.com/jruby/jruby/issues/2035
better exception handling for /maven/releases/rubygems or /maven/prereleases/rubygems directories
more license headers in xml used by tests
more input-stream cleanup - maybe avoid further Bad FileDescriptor Errors
Merge pull request #799 from mkristian/little-fixes

[rubygems] Little fixes
Unterminated scriptingcontainer in UT

Replaced it's explicit creation with the Rule
Merge remote-tracking branch 'origin/nexus-2.11.x' into more-rubygems-tidy