Travis CI: Added jdks

- added open JDK 6
- added open JDK 7
- added Oracle JDK 6
Travis CI configuration changes

- added jRuby head
- added ruby head
- removed ruby 1.9.2
- excluded some strange ruby - JDK configurations
Travis CI configuration changes

- allow ruby-head to fail
Added PKCS12 support for jRuby, fixes #53

* Tested on Java 7 and jRuby 1.7.2
* Still experimental, needs further testing
Added basic unit tests and cred samples, fixes #53

* Moved authN related methods to a new class
* Added basic unit tests and samples of PKCS12 credentials
* Fixed LOAD_PATH for rspec tests to avoid loading
  installed versions of the occi gem; just to be sure
Merge branch 'client-dev' of github.com:arax/rOCCI into client-dev

Conflicts:
	lib/occi/api/client/client_http.rb