tools: pmempool utility

- pmempool utility with the following commands:
-- create - creating pool files
-- info - parsing pool files
-- dump - dumping data from pool files
-- check - checking and repairing pool files
- update scripts for creating packages
- bash completion script
- manual pages and README file
util_check_memory() function returns zero if memory has all bytes equal to the last argument. If the header is zeroed I don't validate the checksum because checksum for all zeros is zero so util_checksum() function would return success. For zeroed header if repair isn't requested I return an error in line 581. The zeroed pool header is considered as corrupted pool file and we can repair it. This can be a case when we overwrite a pool file with zero by accident.