The software manual is updated with the config parameter MTTSkipping description.

Define JVET_AE0057_MTT_ET is placed at the appropriate location in Typedef.h
The Luma channel test condition is updated EncCu.cpp
The threshold value lower range is clipped to 0 instead of allowing it to take negative values.
JVET document number information is removed

# Conflicts:
#	source/Lib/CommonLib/TypeDef.h