Ensure that app/mailers gets created in new plugins

[dgeb]

When calling "rails plugin new [plugin_name] --full", an app/mailers directory was not created in the resultant plugin. This pull request corrects that.

[dgeb]

I am puzzled. This commit shows two diffs, yet shows only a single file in the github viewer. My intention was to also include the following directory by committing a .empty_directory file:
https://github.com/dgeb/rails/tree/3-1-mailers-in-plugins/railties/lib/rails/generators/rails/plugin_new/templates/app/mailers

The reason I wanted to include this directory is that it's apparently missing from:
https://github.com/rails/rails/tree/3-1-stable/railties/lib/rails/generators/rails/plugin_new/templates/app

I don't know why this directory and .empty_directory file seem to be missing from this commit. Perhaps it's there and there is a glitch in the github viewer?

Anyway, the point is that this needs to get into 3-1-stable so that the full app structure is available for new plugins. Thanks in advance.

[josevalim]

Merged. And yes, probably a github bug.

[dgeb]

Looks like the directory made it with the merge, so I guess you're right. Thanks for the merge and the clarification.

[dgeb]

@josevalim - looks like this still needs to be merged with master. For future reference, would it have been better for me to target master and then ask you to backport to 3-1-stable?

[josevalim]

Yes! Could you please provide a patch for master and ping me? :) Thanks for everything!

[dgeb]

@josevalim - Glad to help :) Please see #2339