Sprites - use // comments in generated LESS files

[jammitch]

In sprites, the generated .less file creates mixins that use /**/ comments, which causes the comments to be rendered in the final .css file. If you follow the instructions at the top of the .less file and @import it, then your destination file now has the same comment, even though it obviously doesn't apply to the generated file. The comments in the individual mixins will also be put in the output file. We minify before release, but the comments are still unnecessary in the intermediate generated files.

I don't know if SASS has a similar mechanism for removed comments, but a similar behavior should be adopted there if possible.

[am11]

Same is true for SASS: sass/libsass#424.