fix spelling of hierarchies
Merge pull request #1621 from jasonconkey/fixDocsExtendsTypo

fix spelling of hierarchies
fix error in conditional comments docs
Merge pull request #1631 from hueygroves/master

fix error in conditional comments docs
Support whitespace after + in mixin call
Add test for mixins with space
Merge branch 'char101-patch-1'
Add test case for #1376 (mixin block at end of file)
Fix for mixins at end of file

[closes #1376]
Add test case for #1629 line numbers of error reporting for blocks followed by blank lines
Fix regex for block followed by blank lines

[fixes #1629]
Merge pull request #1634 from visionmedia/mixin-block-problems

Mixin block problems
Using void-elements module.
Release 1.6.0
First class mixins