Generalizing the cronserver to all DB back-ends, fixing scripting issues

Issues addressed:
* We have our own cronserver script, written to be very efficient, but that assumes a sqlite back-end.  However, larger deployments (such as the IDOC) may require a better back-end DB.  @gimick is beginning to benchmark these things, and cannot use our cronserver.
* Some of the scripts that changed in #557 had inconsistent code, and some bugs in the windows scripts.

Changes:
Since we're only running our cronserver every 10 minutes (by default), we can afford to run the chronograph management command.  To accomplish that, I've:
* Made all scripts access Chronograph models, rather than sql-lite specific DB connections
* Fix up the chronograph cronserver management command, which had memory leaks.
* Add software for examining memory leaks
* Fix up OS-specific scripts for cronstart, cronstop
* Fix up the rest of OS-specific scripts to clean their coding, fix bugs.

Testing:
* Tested all scripts on OSx and Windows