Change the second parameter of a regex tagged port_source from being a
filename or wildcard to being a list of filenames or wildcards.
Previously: {"R14", "c_src/*.c"}
Now: {"R14", ["c_src/*.c"]}
Motivation for change is to avoid repeating regexes.
This change makes it possible to assign pre/post scripts to all
rebar commands. This allows users fine grained control over
when scripts and/or shell commands should be executed, where such
extensions are absolutely needed.
Several examples have been added to the rebar.config.sample file.
Add a coverage report similar to the one output to index.html except
that it is output to the terminal if the new rebar.conf option
'cover_print_enabled' is set to true.
