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
In the case you cannot allocate memory here you return an error. Which is ok, but from a style and consistency perspective I would think at this point you should free the pcp->arenas list. I get that the memory will be freed when the command exits but I think its always good style to free what you have allocated. In part to make sure that you always know where you are with allocated memory.