two additional tags for saving color images with libtiff
packbits isn't working correctly
error test for bw compression on RGB file
CHECK: support for int arrays as ifd entries
Renamed test tiff files to 16bit*. They are 12bit data in a 16bit format
Tests for 12bit tiff rawmode
Read only implementation of 12bit tiffs
Comments

Fixes #414
12 bit tiffs come out as 12 bits from libtiff
Removing unused, redundant compression variable. Actual compression setting is in the imagefiledirectory
added generic libtiff en/decoder instead of each compression version
Flags to force libtiff read/write
Test for 12bit image using libtiff
Comments
removing libtiff compression based decoder names
Merge from 12-bit-tiff
Testing default pil implemented compressions with libtiff
disabling bw compression test due to stderr pollution from libtiff
cleanup temp file
merge from master