Hotfix/specific theming

A (supposedly) wrongly placed "return" was exiting the function before completing the theme loading, making the UI unusable.

I removed that return, and moved the code meant to be run after file load in the if {}.

(Incidentally, I found out that the widgets themes weren't loaded, and they were much more familiar this way rather than when they're defined with your custom themes. Lists look like lists, buttons look like buttons, checkboxes look like checkboxes, and +/- buttons appear on spinboxes...)