Branch and commit to backup attempts to solve #161 and #137.

Remains of experiment 1: compiled mixins caching. It slowed down or
crashed the compilation. Turns out that most time is spend in garbage collector then.

Expriment number 2 - minimizing number of created scope objects during the
compilation.
Functional optimized version. Needs refactoring and clean up, but the main
idea works.
Fixed tests and removed sysouts. #161
Clean ups, minor #161
Missing import
Refactoring in progress
Removing old scope which does nothing.
Fixed faulty import
Removing methods and classes.
... refactoring continue ...
Still refactoring
... refactoring ...
Still refactoring
... magic ...
... refactoring almost done ...
 removed warning
more sensible naming and arguments order for factory
finally, something I can live with for next few weeks.
Merge branch 'less-1.1.2-optimizations'