Issue #557 Implemented Contents#raw()
Issue #557 Implemented Content.Smart#content() method
Issue #557 Added unicode characters to test, MkContent to use Base64.
Merge remote-tracking branch 'origin/master' into 557

Conflicts:
	src/test/java/com/jcabi/github/ContentTest.java
Issue #557 Removed stray tab character
Merge pull request #583 from carlosmiranda/557

Issue #557 Content can now be obtained in raw and encoded form