Add support to persist a control value in the user configuration. Fixes Bug #1190797.
Introduced a folder for developer skins
Add support for making skin-created controls persist in the user configuration.

Remove ControlWidgetPropertyConnection loading and saving of control from config.
Just commiting to get rebase done.
Added Disable EQ 'feature', so using contollers with external mixer is now possible. (Like VMS4.1 when not set to POST EQ)
Changing the key name based on review comments
Modified ui file to have Disable EQ checkbox. + fixed some review comments
Review - Changed 'disable' to 'enable'
Review comment, added copywithgain in case we disable EQ
Fixed the checkbox signal, typo.
cleared developer_skins folder
Added res/developer_skins as submodul
Remove ControlDoublePrivate::getUserConfig.
Rely on toDouble returning 0 on failure.
Merge pull request #154 from mspike/eq-disable

Add support for disabling EQ processing.
Enable EQs by default.
Merge pull request #156 from rryan/persist

Add option to persist control values.
Insert a colon (fix)
Add ToolTipRole for sidebarmodel (currently broken)
Delete MixxxUtils and stick the duration string formatting in util/time.h.