implements statmover monitoring on an EC2

This includes a specific 'EmitEvent' for the 'rss' of a process
using Zooko's 'get_mem_used'.  To add new EmitEvents a name is
defined and added to the eventemissions_config.json file.  The
generate script must then define appropriate behavior to:

(1)  Acquire the data e.g. get_mem_used
(2)  Format the data e.g. make_emit_string/structure
(3)  emit the data e.g. the check_call to emit-client

NOTE:  I wrote this some time ago.  We now have the convention of using FilePath
so it'd be nice to refactor file IO to use it soon.
tests that correct series of calls are made by initialize sm source
initialize statmover source on the new SSEC2 during signup

Also tests that initialize sm source receives valid arguments in signup
remove consolekit purge
Use RESOLUTION_MILLISECONDS constant.
Add underscore to constant names.
Update comments in get_mem_used

Note:  We may add a dependency on pyutil instead
of reimplementing.
Make units explicit for get_mem_used.
make if elif whitespaces consistent with style
Handle unknown type as NotSupported exception.
indent to improve style
Move _check_all_done to the end of the test method.
Add necessary \n to eventemits.