Added a process info checker with groups management
Import pprint only for tests
Added psutil to requirements
Refactoring of process checker
removed debug code
Improved docs
Removed unused constructor
Removed sys.path.append
More explicit gauge name
Added info on exact_match in the doc, fixed an error in the doc
removed import sys
naming refactoring
Creating a global instance of process iterator
moved process interator inside check method
Added real memory info and exceptions handling
fix for flaky test
Merge pull request #460 from DataDog/watchdog_flaky_test

Fixing a flaky watchdog test
Merge pull request #434 from mastrolinux/process-management

Process management
Merge branch 'master' of github.com:DataDog/dd-agent into nagios_checksd