added method to check if a key exists
added method to set all flux strings
van Leer splitting more appropriate for Ma=6 under-expanded jet ...
moved to one flux and fixed a silly typo
debug off
first working version of coupled solver
sometimes the program would not stop without exit
adapted to current code structure
possibility to limit number of thread (required to run on a GTX-580)
renamed  accessIndex() to getIndex()
patch index will be copied to GPU as well
removed debug option