Create Makefile_Softbound

Rename Makefile_Softbound to Makefile if you want to build ncompress with Softbound support. In this case clang compiler will be used instead of gcc. The required options are:  
OPTS    += -fsoftboundcets -L /home/username/Desktop/Softbound/softboundcets-34/softboundcets-lib -lm -lrt

Warning 1: change path in the option -L /home/username/Desktop/Softbound/softboundcets-34/softboundcets-lib
to your own path to 'softboundcets-lib' directory  on your machine 

Warning 2: Softbound can be used only on 64-bit architecture. Softbound author said about it here: 
http://lists.cs.uiuc.edu/pipermail/svadev/2012-May/000251.html