Name AMD modules to support loading multiple ones from minified bundle

[fredrikekelund]

When the entire minified bundle (load-image.all.min.js) is loaded with require.js, require.js has no concept of which of the modules in that file is which unless we explicitly provide names for them. The developer still needs to tell require.js that this file contains all of the referenced modules though, so I added a note about that in the README.

[blueimp]

The minified file is just provided as a convenience.
For most projects, the source files should be used individually and the project build process should handle minification of all JS assets.
Therefore I don't see a need to use named modules, as developers who use RequireJS should use the individual source files and will probably use the RequireJS optimizer (r.js) to bundle their assets.