Also filter out .ps1 files
Add @external_resource attribute, closes #2455
Remove usage of :filelib functions

This is to work around a regression in 17.1 where many
:filelib functions were broken. More information read:

http://erlang.org/pipermail/erlang-bugs/2014-June/004465.html
Change precedence of & to not special case /
Update CHANGELOG
No need to reverse a list when building an iolist
Use iodata_to_binary in join/2 and map_join/3

Everything is previously converted to a string using
the String.Chars protocol, so we can just treat it
as iodata.
Fix regression when case is used inside cond head