Fixes #1147 (type-mismatch) +features

Added helper: /proc/findchar(haystack, needles, start=1, end=0)
works like findtext except it finds the first occurrence of one of the characters from the needles string, within haystack.

Permissions can now be removed as well as added, by replacing the + with a -. e.g. +BAN adds bans permissions, -BAN removes them. This applies to admin_ranks.txt and the permissions panel.

Verb overrides are now possible for admins_ranks. Specific verbs can be forced-on, or forced-off via keywords like +/client/proc/mimespeak or -/client/verb/ooc. This applies both to admin_ranks.txt and the permissions panel. SQL system is not compatible.

admin_ranks are now datums. This means admin_ranks actually behave more like permission groups as intended.
When you temporarily modify an admin's permissions via the permissions panel, their rank_name is appended with "([ckey])". This prevents modifications to their rights affecting everyone.

admin rank names now support - _ and @ characters (since ckeyEx() does not strip these).

SQL permissions system was modified. SQL databases will have to be updated or they will no longer work.

**WARNING: admin_ranks.txt and admins.txt format has changed slightly! You will need to redo those txt files!**