Fixed issue with converting POS filenames to KRTD
Fixed issue with converting POS filenames to KRTD

When producing the KRTD filenames from the POS file names, the pos2krtd
tool was being too agressive about striping file extensions when more
than one '.' was in the file name.  This change strips the extension at
the last '.' instead of the first.

linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk