add new literature

Kirk
Rodrigues
added cut off

by R and Z
tests
little optimization
cutoff summation by volume for all pixels
TC
TC
TC
Merge remote-tracking branch 'origin/Direct-Summation'

Conflicts:
	.gitignore
	samples/template.xml
	x64.debug.common.dll/Image.dll
	x64.debug.common.dll/Image.exp
	x64.debug.common.dll/Image.lib
	x64.debug.common.dll/LMultiSlice.exe
	x64.debug.common.dll/Layers32.exe
	x64.debug.common.dll/Layers32.exp
	x64.debug.common.dll/Layers32.lib