Change: re-implement rt feature in sysguard module

Based on review:
1) get rid of shared memory, change rt check to a per worker basis.
2) add a new directive to provide "and" functionality among load and rt
3) use log handler to update rt node instead of hacking the code
directly
4) modify test cases to match the new behavior of this feature

Signed-off-by: Paul Yang(InfoHunter) <paulyang.inf@gmail.com>