- Mocha.prototype.reporter is now Mocha.prototype.reporters and can take the same types of arguments
as before, plus a list of reporter names as a comma separated string, or a list of constructors.
This allows using more than one reporter.
- Replaced command line switch --reporter <name> by --reporters <name>,... so that users
can pass a comma separated list of reporters on the command line.
- The old --reporters command line switch used to list available reporters is now --list-reporters.
- Revert the change of command line interface, --reporters is back to --reporter and --list-reporters
is back to --reporters.
- Use the "list" arguments parser for --reporter now.
- Mocha.reporters does not accept a comma-separated string of reporter names anymore, this is the command line parser's job
to parse the --reporter command line switch and provide an array to this function.
Merge branch 'master' into multiple_reporters_support

Conflicts:
	bin/_mocha
	lib/mocha.js
Keep original Mocha.prototype.reporter (singular) for API compatibility
Add/fix tests for multiple reporters