Fixed multiple issues

This commit fixes multiple issues.
1. The conversion to use 'jailpath' as the primary mechanism for
tracking the jail's location. This involved editing nearly every single
file in the repository to no longer use $config['thebrig']['rootfolder']
. $jail['jailname'], but instead use simply $jail['jailpath'].
2. The input modification/validation to ensure that every folder gets
stored with a trailing /. This involved modifying every instance of
$jail['jailpath'] . /work to be $jail['jailpath'] . work.
3. Removed all instances of $_POST as an l-value. If any input
modifications were carried out, they were done to the copies housed
within $pconfig.
4. Repaired the tarball display code within functions to reflect the
changed index keys after the preg_grep() operations.
5. Added a date/timestamp to the filename of a jail's backup, to ensure
no jail backups get overwritten.
6. Modified thebrig_start and jail_start to no longer have CRLF (which
was causing errors). Also, added additional logic to jail_start, so that
it is run at every boot, but only creates rc.local.conf and starts the
jails if they are not already started.
7. Moved all of the logic and output definitions within _check so that
the code was eaiser to understand.