Add advanced selectors rearrangements

[GoalSmashers]

E.g.

.one{color:red;margin:0}
.two{color:#fff}
.one{font-size:12px}

into

.one{color:red;margin:0;font-size:12px}
.two{color:#fff}

It should be possible to rearrange & merge selectors if:

• any intermediate selectors ones do not redefine properties moved
• any intermediate selectors are do not override moved one (html element ones, classes are unsafe)