Rewrite mode processing system
mode: Add mode stacker vtable
core/mode: Kind of fix /MODE for channels
chan: Sort channel mode bits
mode: Fix debugging with lists
mode: Implement list handling.
core/mode: Allow lists to be sent to the user
core/mode: Buffer-ize /MODE cmode stacker
core/mode: Implement TMODE
Add mode context sync
.gitignore: Add tags
mode: Split MODE_UNSET_ONLY into MODE_NO_RESET and MODE_NO_SET
mode: Add MODE_FORCE_ALL flag, allowing access checks to be bypassed
user: Create umode infotab and context
user: Resetting umode bits should use &= ~, not |=
mode: Add simple buffered mode stacker
core/mode: Implement user /MODE
core/euid: Process user mode parameter
core/sjoin: Use new modes API
chan: Implement +l, +k, and +f