scriptEngine and debugger as sharedpointers
preventing segfault + progress
damn weird bug!
it's alive!
Merge branch 'master' of git://github.com/mixxxdj/mixxx into one_script_engine
Disable saving of effect chains since loading is disabled.

Prevents committing to an XML format before we are ready.
Delete unused ControlObjectSlave in EffectSlot.
Re-add EffectSlot::debugString() and update EffectChainSlot::debugString().
Typo fix in method name and check for NULL controls since Samplers and
PreviewDecks do not get EQ effects.
Aliases should live near the code that they alias to.
Remove double-hash lookup in ControlDoublePrivate::getControl.
PRable
pr review
Refactor equalizer rack and quick effect rack.

* Create dedicated EqualizerRack, QuickEffectRack, and
  StandardEffectRack classes.
* Move all per-rack initialization into a method of the sub-class.
* Share common code between EqualizerRack and QuickEffectRack with a
  PerGroupRack parent class.
* Move group formatting methods for rack, chain, and effect to the rack
  sub-type class.
* Keep a strong reference to racks in DlgPrefEq to protect pointer
  usage and eliminate assumptions that the pointer exists.
* Remove filterDepth / filter CO aliases.
Some code safety changes.
Delete EffectRack::loadEffectToChainSlot().
Merge pull request #399 from demos/one_script_engine

Use one script engine and one script debugger to avoid slow down of the skin parsing
Don't print errors about not being able to parse empty size policies.
Unify rack/chain/effect/parameter association logic for effect widgets.

Add support for associating with rack and effect unit by group.
Add QuickEffect1 superknobs to the mixer column in Deere.