forms: Preserve data for help topic fields

This patch fixes a glitch in the dynamic forms processing system preventing
the validation and capture of data for help topic custom fields. Now the
`$vars` managed inside of `Ticket::create` is connected directly to the
`DynamicFormEntry` created for the data rather than using the magical
connection to `$_POST`.
session: Override PHP default for session lifetime

The PHP.ini default is 1440 seconds (24 minutes). This should be configured
to something significantly higher so that the settings in the admin panel
concerning session timeouts are relevant.

Ideally, the settings from the control panel would be used, but currently
there is an inter-dependency between session and config startups.
email: No bounces for system alerts

Send an empty return-path envelope when sending out system alerts. If they
should happen to bounce for any reason, they should not return to the system
and create tickets.
Fix typo in suggested permissions for config file
forms: Phone numbers with no digits = invalid

Previously, the characters would be removed and the data would be considered
empty which would bypass validation and clear the phone number on save
rather than triggering a validation error.
Fix XSS vulnerability on user's name

Names parsed from incoming emails are stored in the database as is. This
pull request addresses potential XSS vulnerability due to improper display
of unsanitized names. Going forward names will be scrubbed on create.
Fix potential XSS vulnerability on user's name

Add other locations as well a failsafe for the htmlentities() call
Add release notes for v1.8.5