Added bootstrap (complete package, with templates), incl. proof of concept

This opens the gates to fancier standard GUI elements.
Doesn't change the fact that a directory input GUI still needs to be done, probably as directive
Attempt to get a slider working - FAIL

Turns out it's too flimsy, and not so well documented.
Getting a simple int slider to work seems much harder than it should be.

2h wasted on this - final issue was that it needed a window resize event
to setup the knobs correctly.
Without slider, it works within a minute.

Lesson learned here
Added seal format selector
Implemented an html-only preview of the respective godi commandline
Added tooltips to every relevant GUI element

SPOD will now default to 1 as well