Remove declaration for single selector

[ol0lll]

If there are multiple selectors in one rule and a declaration should be removed for one of them, the rule has to be copied.
a, .link { color: red; }
should result in:
.link { color: red; }

Notation:
remove { a { color } }

[ol0lll]

implemented by creating a new rule for specified selector and removing declarations only there.

[tjwelde]

This was removed and might be introduced again: See #1