messages: require.js messages

* Refactors the messages/add template to use require.js.
* Loads jQuery UI modules individually.
* Fixes the jquery timepicker addon shim.
* Moves boostrap.js back into the jquery bundle (because `ui/button` shouldn't be loaded by default anymore)

@kneczaj some of the answers for #2039 are here, I hope.

**Screenshots**

![write a message - atlantis institute of fictive science 2014-08-06 09-00-28](https://cloud.githubusercontent.com/assets/1388/3823313/8fb3af50-1d37-11e4-8708-60810f889107.png)

![write a message - atlantis institute of fictive science 2014-08-06 09-00-59](https://cloud.githubusercontent.com/assets/1388/3823314/8fd8e716-1d37-11e4-9e29-5b82720c6019.png)
We were discussing it already with you and Javier, and I am sure we decided that there will be:
- base bundles for js and less/css loaded globally
- separated ones for every module: one for js and one for less/css.
This is the reason. For persons not familiar with the topic - this solution creates a simple and unified way of extending the bundles in an overlay.

As @jmartinm is on holiday right now he cannot support me here, but maybe @lnielsen-cern heard about this convention and can write a word about it.

The mentioned above result of the discussion was the reason why this code was written and merged https://github.com/inveniosoftware/invenio/pull/1953

I am for coherent rules here disregarding if we have much or less css inside a file. If you want to modify the convention which we decided to use, please introduce us a proposition with simple rules and some arguments for it. I think we should write it down somewhere too, because spoken agreements don't work as we see here.