Reactivate HTML Menu unit tests as part of the test suite

[lkcampbell]

This PR is from the following posting:
https://groups.google.com/forum/#!topic/brackets-dev/gJVZgXFq50o

[redmunds]

To keep API simpler, make these changes:

1. Keep only a single API call with original name: createTestWindowAndRun
2. Add an optional (3rd) parameter something like: function createTestWindowAndRun(spec, callback, options).
3. New parameter is an Object (not a boolean), so new options can be added without adding any new params.
4. Since new parameter is optional, then existing calls will not need to be updated. It only needs to be specified on new calls. If options object or options.hasNativeMenus is not specified, default is brackets.nativeMenus.

[redmunds]

Done with review. This looks pretty good. Just some API cleanup.

[lkcampbell]

@redmunds, API changes made.

[lkcampbell]

Edited description to remove new API functions since they are no longer part of the PR.

[redmunds]

This form is simpler, and it also checks for null and empty string:

    if (params.get("hasNativeMenus")) {
        global.brackets.nativeMenus = (params.get("hasNativeMenus") === "true");
    } else {
        global.brackets.nativeMenus = (!global.brackets.inBrowser && (global.brackets.platform !== "linux"));
    } 

Also, how expensive is the call to params.get("hasNativeMenus")? Should it be stored in a var so it's not called twice?

[redmunds]

Second review complete.

[lkcampbell]

@redmunds, code updated.

[redmunds]

Looks good. Merging.