rebar.config.script that checks for maps support in the release rebar
  is using to compile. hopefully this is the same release as the
  artifact is being run on
add a check for env var to optionally compile without support for
  erlang maps
switch to feature detection rather than trying to figure out from
  compiler version/release whether maps should be supported
correctly pass compile opts to rebar
refactor out copy/pasted encode methods
fix rebar.config.script for < otp 17.0
add a rebar.config option to disable maps
remove mention of internal state manipulation from CHANGES, leave
  experimental for now
update README and CHANGES with details for 2.0