update variables, and insert into facts table

Summary: Moving variable updating to the collectd daemon.

Test Plan: none

Reviewers: ankur

Differential Revision: http://grizzly.memsql.com/D3977
Added network testing module

Summary:

 * Kick off a bandwidth or latency test against a MemSQL server
 * Lots of little tweaks here and there
 * Refactored out some shared logic into sql_utility

Test Plan: ankur

Reviewers: ankur

Differential Revision: http://grizzly.memsql.com/D3978