pluginclient cr=apply in option value textbox, add loop_mode for vwdw

playback, add swap track up/dn, change reset_cache to use ref counts,
change gang_media,gang_chans pngs, add shift switch gang mode btn, tweak
mask_engine for high cpu count, change patchbay btn layout, fix track
redraw interrupted by index builder, fix scollable textbox resize
positioning, wsiwyg gang_master tweak.