FitHiChIP + HiCPro - Release 3.0

Changes done in this release:

1. Main executable is modified for more stringent checking of the input paramters, HiC-Pro installation directory.
2. Minor changes of the source code of merging nearby interactions.
3. Updating sample configuration file and sample test scripts.
4. Bedtools latest version (2.26) support and corresponding adjustment in the code