Experimental reorganization of modules and APIs to employ RequireJS/AMD
(Asynchronous Module Definition) with radical simplification of the
project's build system.

Note that some third party libraries that use browser globals are still
loaded in a classical way, using SCRIPT tags before the require.js tag.

Also includes changes from the experimental support for HTTP byte range
fetching from zipped EPUBs.

Change-Id: I1e621ab4ef1105487afd74abdaf87d23b10d2df2
Small fix to event handling in sample application

Change-Id: I8c408cf1d070609436b5fd7ea7d94006fc916a38
Add zipped EPUB sample for internal links

Change-Id: I57e79e3eaaa44f4f60ffb286787911e19a4ea7dd
Add missing dependencies between RequireJS modules.
Add dependencies between Rake builds of different epub modules.
Simplify samples project Rakefile and make its build dependent on builds of epub
modules.
Eliminate directory prefix from RequireJS epub module names. Use built
minified versions of modules in the sample test application.
Fix a race condition with asynchronous loading of test site's event
handling script.
Merge pull request #27 from aadamowski/requirejs-experiment

Reorganization of epub JS modules and build system for RequireJS/AMD, support for remote zipped EPUB files using partial HTTP fetching