rustdoc: Remove definitions of spawn_listener and spawn_conversation
rustdoc: Fix some search-and-replace fallout
rustdoc: Remove another use of oldcomm
rustdoc: Remove stray mode
rustdoc: Convert to pipes
core: Remove oldcomm
rt: Remove ports
rt: Remove circular_buffer
rt: Remove get_frame_glue_fns. Unused
rt: Remove some unused upcalls
update compile-fail/map-types.rs to use hashmap
cat modernization (cleanup of a run-pass test)
remove old StdMap trait

this has been replaced by core::container::Map
rm commented out std::map code from json module

it was replaced by LinearMap
rename map -> oldmap and mark it as deprecated

LinearMap is quite a bit faster, and is fully owned/sendable without
requiring copies. The older std::map also doesn't use explicit self and
relies on mutable fields.