Keep @for environment inside @content block. Fixes #120
Keep @while environment inside @content block. Fixes #121
Merge pull request #122 from sergeylukin/mixin-content-for-env

Keep @for environment inside @content block. Fixes #120
fixes a bug when using functions in mixin_content
Merge pull request #130 from timonbaetz/master

fixes a bug when using functions in mixin_content