Minor updates
show es health, http status code fix, smtp plugins, silly plugin compile check, 2G max tcp session libnids crash fix, db.pl uses action for verification, better viewer decoding, better date selection, better email display

* Admin users now see ES health with mouseover and clicking takes to ES head plugin
* When capturing HTTP traffic sometimes the status code wasn't recorded
* Can now have SMTP plugins
* When plugins load we now have a simple check to see if it was compiled against the same version of the API
* Only save up to ~2Gs of a single tcp session to work around a libnids crash (uses signed int)
* db.pl requires you to type the action name instead of just YES
* viewer now does a better job decoding attached files for HTTP and SMTP
* Can now enter extact date/time in custom mode
* Cleaned up email display