(MCO-83) Add ability to sort rpc results

This commit adds the --sort flag to rpc clients which will sort
the rpc results by sender name before processing.

This is done by implementing the <=> operator for the RPC::Result
class.
Add MCollective::Util#field_size and MCollective::Util#field_number
Use dynamic column sizes in various places
Merge pull request #215 from raphink/dev/unresponsive_dynamic_formatting

Dynamically adapt column size in lists
Merge pull request #217 from ploubser/mco-83

(MCO-83) Add ability to sort rpc results