Help file: reorganize white space
Help file: fix minor errors
Help file: rephrase configuration intro
Help file: rephrase Erlang.*ShowErrors commands
Merge pull request #6 from hcs42/master

Find rebar.config, new options (outdir, xref, load, copy)
Add options rules
Add help tags generation to README
Merge pull request #7 from hcs42/options_rules

Options rules
Fix: use local makeprg

The previous version set the global makeprg, so makeprg was set for other
(non-Erlang) buffers too.
(#8) Apply all rebar.config files

So far we found the closest rebar.config file when walking up the directory
tree from the source file and used that config file.

Now we always walk up until we reach the root directory and use all
rebar.config files to find the include files and BEAM files. We still use only
the closes rebar.config file to determine the other compilation options,
because that's what rebar seems to do.
Merge pull request #9 from hcs42/more_rebar_configs

More rebar configs
Correct message when called without a parameter
Return 2 in case of incorrect usage

Just for the sake of consistency.
Add log_error/1
Add paths and includes to fix plain app projects

So far we found code paths and includes for project layouts (where we have an
"apps" directory and rebar.config lists the application directories).

Now the plugin also works for plain app projects (where src, ebin and include
are all next to rebar.config).