Allow disabled options in select, fixes #183

Not sure if the selectConfig.disabledPath is needed, but kept it for consistence with valuePath & labelPath.
Default option disabled by default
Fix evaluatePath returning obj if value not found
Merge remote-tracking branch 'origin/master' into patch-1

Conflicts:
	backbone.stickit.js
Fixed broken tests by stoppig the defaultOption from being disabled by default
Added tests for disabled attribute on select options
Fixed failing test caused by inconsistent browser behaviour
Merge pull request #238 from yamsellem/patch-1

Allow disabled options in select, fixes #183