postscript image encode overlooked bit alignment in memory assignment

[Daniel J S. <dan...@ie...>]

We obviously never tested this imshow(A,A,A) routine... found a bug in my image encoding for the palettes of size larger than 2^8 such that the routine adds a half byte per line:

	* term/post.trm(PS_encode_image):  The computation for the max number
	of required bytes for encoding the image didn't take into account that
	there is 8 bit alignment (potentially additional 7 bits) at the end
	of each image line.  The encoded image was written outside memory on
	the heap and corrupted when cleared.  Fixed, and added an assert()
	test, after the fact, to compare encode size against memory size.

This should be the last one for a while.

Thanks,

Dan