Update keylogrecorder.rb

Added -k option which, if provided, will attempt to kill the old pid after a successful migration.

Fixed a bug where a blank line would get added to the log file every polling interval if no keystrokes had been detected during that interval.
Update keylogrecorder.rb

Removed redundant code, added error checking.
Merge branch 'master' of github.com:shellster/metasploit-framework into shellster-master