Issue #509 Implemented RtReleaseAssetsITCase, corrected URI in
RtReleaseAsset
Issue #557 Implemented Contents#raw()
Issue #557 Implemented Content.Smart#content() method
Issue #557 Added unicode characters to test, MkContent to use Base64.
Issue #509 Updated Javadoc comment
Issue #592 NotNullTest was implemented
Issue #592 Functional fixes
Merge remote-tracking branch 'origin/master' into 557

Conflicts:
	src/test/java/com/jcabi/github/ContentTest.java
Issue #557 Removed stray tab character
parent 0.17 and qulice 0.4.1
Issue 459. Repos.remove() javadoc changed: added notification about admin permissions.
Issue 459. Repos.remove() javadoc modified according to code-review notices.
Merge pull request #615 from aistomin/Issue-459

Issue 459. Repos.remove() javadoc changed: added notification about admi...
Issue #607 Now using random keys in RtDeployKeysITCase
Merge pull request #616 from carlosmiranda/607

#616: pull request Issue #607 Now using random keys in RtDeployKeysITCase
Merge pull request #538 from carlosmiranda/509

#538: pull request Issue #509 Implemented RtReleaseAssetsITCase
Merge pull request #601 from longtimeago/592

#601: pull request Issue #592 NotNullTest was implemented
Merge pull request #583 from carlosmiranda/557

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