Reload cartridge repository cache when mcollective recieves a HUP signal

Note: Sending USR1 to mcollective in F19 causes 100% cpu usage.

Our code doesnt need full daemon reload, only reload of cache so instead of using USR1, I am using HUP to cause cache to reload.

Since we should not execute any significant code in signal handler, marking cartridge repository as needing an update and doing it in a lazy manner.