Feature: rt support in sysguard module

Two new directives are introduced:
*) sysguard_mode and/or
*) sysguard_rt rt=time period=time action=some_location

This feature introduces the ability to limit requests based on "rt".
Also, all the measurements can be considered in an "and" or "or"
relationship due to the new "sysguard_mode" directive.

Test cases are included.

Signed-off-by: Paul Yang(InfoHunter) <paulyang.inf@gmail.com>
Merge pull request #476 from InfoHunter/sysguard-rt.final

Feature: rt support in sysguard module