Started work on support for tabular inlines in tabbed translation fields (issue #66).
Merge branch 'master' into tabbed-tabular-inlines
Refactored tabular inline treatment. Introduced a new TabularInlineGroup which stores information about its contained table. It handles most the complexity like updating the table or retrieving its translation fields through a TranslationFieldGrouper. It can return either all translation fields for the initial regrouping of columns or translation fields based on a jquery selector to handle the add another links.
Fixed some visual glitches in tabular inlines.
Refactored MainSwitch into a singleton.
Moved update tab functionality to MainSwitch.