Fixed build warnings.

- All plugins have version information.
- Fixed deprecation warnings.
- GPG passphrase from env variable.
- Include OSSRH snapshot repository.
set license-plugin strict check properly
Strict check in the proper place.

- Update license up to 2014
License text update
Added travis build information
Travis build status image.
New assembly plugin requires an assembly id.
More informative test failure messages.
Exclude .travis.yml from license check.
SuppressWarnings annotation in for loop confuses cobertura.
Run javadoc plugin at packaging time.
Fix javadoc warnings.
Reformatted header.

Source format confuses the license check plugin.
Remove harcoded timestamps in error message.

Hardcoded timestamp messages produce test failures on different
timezones.
Slack notification for travis builds.
Merge branch 'develop' into fix/VOMS-529

* develop:
  Slack notification for travis builds.
  Remove harcoded timestamps in error message.
  Reformatted header.
  Fix javadoc warnings.
  Run javadoc plugin at packaging time.
  SuppressWarnings annotation in for loop confuses cobertura.
  Exclude .travis.yml from license check.
  More informative test failure messages.
  New assembly plugin requires an assembly id.
  Travis build status image.
  Added travis build information
  License text update
  Strict check in the proper place.
  set license-plugin strict check properly
  Fixed build warnings.
Reformatting.