ENH: builder components now using tabs for (optional) param categories
ENH: only setNameColor (for extended code params) if name exists
NF: added psychopy.data.checkValidFilePath() replaces code in builder scripts

This wasn't just added for kicks - it was needed to make it possible
to add customised file names for experiments. If they're custom then
they need to check the compile the folder name later so we need a
better way to check the path is valid
NF: custom data filenames are now possible from Builder experiment settings
FF: fix to new system for settings loop controls (was failing on type switch)
FF: Component Name validator working again after addition of param categ tabs

Apparently child panels need to be explicitly validated as well as the
parent.

I also removed some old debug lines and several lines of old, commented-out
code