Merge pull request #49 from jcabi/master

merge to my repo
Merge pull request #50 from jcabi/master

merge from master to my branch
Issue #468 - MkPullComments should be able to fetch all comments of a pull request
Merge pull request #494 from lthuangiang/issue468

#494: pull request Issue #468 - MkPullComments should be able to fetch all comments of a pull request
Issue #446 Contents.create() now accepts JsonObject
Issue #446 Fixed comment
Issue #446 Fixed comment
Merge pull request #497 from longtimeago/446

#497: pull request Issue #446 Contents.create() now accepts JsonObject