Add MailScanner Rule editor functionality

Adds MailScanner Rule Editor functionality
MailScanner Rule Editor Update

Add install docs and cron script for auto-reload of MailScanner after
rule edit
MSRE - fix documentation
MSRE - fix docs
MSRE - Remove superfluous variables
MSRE - treat blank lines in rules as comments
cosmetic change
MSRE - Updated Changelog
Explicitly close the file we just created
MSRE - Updated style.css

Oops, forgot to upload updated stylesheet
MSRE - Allow "Virus:" keyword in rule files
MSRE - "Virus:" keyword can only be at start of rule
MSRE: Properly fix 'Virus:" keyword handling
MSRE - Move Number of columns define into msre_edit.php
MSRE - Fix 'and' handling, change form layout

'and' handling in the original MSRE was very broken.  Now fixed to do
the right thing.

Form layout changed to give a line for the 'action' which could be much
longer than a simple 'yes' or 'no'
MSRE - ensure default rule is always the default

Don't allow an overzealous editor to change the default rule into any
other kind of rule
MSRE: Update Changelog
Fix handling of escape characters in posted form
MSRE - Update Changelog
MSRE - fix keyword case-sensitivity

Treat "Fromorto:" the same as "FromOrTo:", etc