Added condition to check if HEX code contain only valid characters
Added more flexible check for HEX color code. Also error is now less specific.
Added another test case for missed space in color definition
Fixes e("").
Remove the "done" message displayed at the end of the compilation with Rhino.
If the end line is comments, the modify-var option will have no effect.
window.ActiveXObject in IE11: fix boolean casting

in Internet Explorer 11:
window.ActiveXObject // function ActiveXObject() {[native code]}
!window.ActiveXObject // *true*
Remove copyright from licence so we only have one

 up to date copyright in the readme.
remove 0.8. 0.8 works but only if you don't use

 any dependencies. Support will be removed from the package.json in 2.0.0
Update README.md

Add optional dependencies
Make clean-css truly an optional dependency.

The less parser treated clean-css as a required dependency when the cleancss
option was used. This causes an error when optional dependencies aren't
installed.