Make provisions for more default quant tables
Add new quantization tables

New quantization tables tuned for PSNR-HVS are added.
Per-coefficient lambda weights are now derived based on the
quantization table entries.
Add quantization tables

Add various quantization tables suggested in #84
Still need to do chroma
Adjust lambda parameters

Parameters were retuned for grayscale and quality range 0-100
Add switch to cjpeg to select quant table

Replace -flat command line argument with more generic -quant_table
argument that selects one of several predefined quantization tables
Merge branch 'master' into qtable

Conflicts:
	cjpeg.c
	jcdctmgr.c
	jcparam.c
	jpeglib.h
	rdswitch.c
Clean up qtable code and change defaults
Merge branch 'qtable'

Conflicts:
	jcparam.c (resolved)