- decimation fixes, accumulation radar accomodation, path searching improvements

radblockproc - improved error checking, support of slightly different
accumulation-radar format, use of GIMP projection for x/y
pickgui - improved searching for radar data within established path
structure, support accumulation radar support
mergegui - improved searching for radar data within established path
structure, minor fixes for layer SNR measurement
fencegui - fixed decimation (one change now does both GUIs)