perl5/Socket6, perl5/IO-Socket-INET6
spamassassin fixes

Apparently there were some optional modules installed at build time, so
SpamAssassin couldn't cope without them at runtime. Additionally, make
it find gpg and work with IPv6 resolvers.
JSON-MaybeXS: require JSON-XS
multiarch postgres93
add a bunch of perl modules for rt4
add perl5/CGI (need newer version than is in perl5.20.1)
replace Alt-Date-Extract-SHARYANTO with Date-Extract

apparently metacpan maps Date::Extract to the former distribution, but
rt4's module checks are not ok with that.
add rt4
rm perl5/Alt-Base

not needed; was dependency for Alt-Date-Extract-SHARYANTO