Hall can now perform customizable filtering on incoming messages.
Uses a `|=(telegram ...)` supplied by /app/hall/filter.hoon
/- hall :: structures
/+ hall, hall-legacy :: libraries
/= seed /~ !>(.)
+/= filter-gram
+ /^ $-(telegram:hall telegram:hall)
+ /| /: /%/filter /!noun/
+ /~ |=(t/telegram:hall t)
+ ==
::
::::
::
?. (so-admire aut.gam) +>
:: clean up the message to conform to our rules.
=. sep.gam (so-sane sep.gam)
+ =. gam (filter-gram gam)
:: if we already have it, ignore.
=+ old=(~(get by known) uid.gam)
?. &(?=(^ old) =(gam (snag u.old grams)))
