The custom queries are configured in rebar.config via the tuple
{xref_queries, [{query(), query_result()},...]}.  The implementation
passes the query() string to xref:q and compares the return value with
query_result(). It will result in an error if they do not match.

The following configuration, for example, is the same as running the
xref check undefined_function_calls. It additionally filters
ejabberd_logger:*_msg/4 from the result as these functions are generated
on execution by ejabberd and not available at compile time.

{xref_queries, [{"(XC - UC) || (XU - X - B -
                 (\"ejabberd_logger\":\".*_msg\"/\"4\"))",[]}]}.

This patch also modifies the build process of this package by running a
custom query instead of doing a diff against a static xref_warning file.

This change adds the ability to use alternate urls for downloading
dependencies. To make use of alternate urls run:
rebar get-deps alt_urls=true

* consolidate options
 * add support for building executables

This patch allows users to specify the directory in which common_test
source files can be found. Most common_test suites are integration,
rather than unit tests and keeping the sources apart from test sources
for other frameworks such as eunit and PropEr is a useful feature.

This patch updates rebar_core to look for missing plugins (i.e. those
that aren't found on the code path at runtime) in a configurable
plugin directory, and dynamically compile and load them at runtime.

By default, the directory "plugins" is searched, although this can be
overriden by setting the plugin_dir in your rebar.config.

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 patch adds a `ct_extra_params` option to rebar.config, the value
of which is appended to the shell command when executing common test.

Add no_debug_info option.
Remove debug_info=1 option.

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.