#15 Palette management

[Martijn Jasperse]

It is desirable to have automatically updating palettes ("synchronised") that stock with new VIs that get added. Implemented in 9f21f25b73f3 but the LLB directories turn up.

Consider renaming directories to begin with _ so that they are left out of the auto-list, or adding a blank dir.mnu (or similar) to prevent them showing up