Feature: Allow testem to run specific test module

Adds `--module` command line option to `ember test` and `ember test
--server`. The `--module` option tells QUnit to run the specified test
module.

Example usage `ember test --module "Module Name Here"`
Enhancement: `ember test` can accept both `--module` and `--filter`

This allows testing a specific module for all tests containing a given
string.

Example usage all tests in the `fooModule` containing the word `bar`
`ember test --module "fooModule" --filter "bar"`
Refactor: better organized code to build up query string
Merge pull request #2532 from JarrodCTaylor/master

Feature: Allow testem to run specific test module