Enabled new opendream pragmas
Fixed some runtime access check operators (`:`) around the codebase (not
all, some are unfixable as they're used in macros)
No player facing changes (hopefully)
Fixed all datum[index] accesses, they are considered undocumented
behavior and fail from 515.1641.
Flipped the OpenDream pragma for the above to emit an error instead of a
warning.
Unified most of the procs into one definition, so there are no duplicate
around the codebase.
Marked some of the above as overridable if a good enough case can be
made for them (eg. external dependency or unlikely to be used).
