Added a config. file parameter for ISP

cfg/encoder_intra_vtm.cfg

cfg/encoder_lowdelay_P_vtm.cfg

cfg/encoder_lowdelay_vtm.cfg

cfg/encoder_randomaccess_vtm.cfg

doc/software-manual.tex

source/App/EncoderApp/EncApp.cpp

source/App/EncoderApp/EncAppCfg.cpp

source/App/EncoderApp/EncAppCfg.h

source/Lib/CommonLib/Slice.cpp

source/Lib/CommonLib/Slice.h

source/Lib/CommonLib/TrQuant.cpp

source/Lib/CommonLib/TypeDef.h

source/Lib/DecoderLib/CABACReader.cpp

source/Lib/DecoderLib/VLCReader.cpp

source/Lib/EncoderLib/CABACWriter.cpp

source/Lib/EncoderLib/EncCfg.h

source/Lib/EncoderLib/EncLib.cpp

source/Lib/EncoderLib/IntraSearch.cpp

source/Lib/EncoderLib/VLCWriter.cpp