Adding abort and interrupt signal handling for long running mode.

chopshop
  - added signal handler for abort signals
  - passed sigint to surgeon and nids processes

  ChopLib.py
  - stored surgeon in choplib object so is accissble from chopshop
  - added handler for abort and interrupt in nids process

  ChopNids.py
  - handling of abort and interrupt variables in core to exit nids appropriately

  ChopSurgeon.py
  - added handler for abort and interrupt in surgeon process
  - removed longrun from surgeon_proc_list function b/c it is no longer used
    * needed to use self.long to update the variable in the signal handler
  - added stopread to self so could be set in signal handler
fixed misspelling in comment
cleanup & fixes

chopshop
  - removed signal pass to nids b/c removed debug code that terminates nids in ChopLib.py

ChopLib.py
  - uncommmented coded that was commented for debugging

ChopNids.py
  - removed interrupt variable handler
  - condensed code to fix multiple calls to nids.next()

ChopSurgeon.py
  - added long back to surgeon_proc_list args
  - set self.long inside surgeon_proc_list explicitly
  - condensed code
removed unused signal handling code
Merge pull request #24 from AetherDeity/signals

Adding abort and interrupt signal handling for long running mode.