[WIP] Reincorporate bookmarklet build

This commit adds back the configuration needed to build the bookmarklet.
I've moved the bookmarklet from contrib/ to src/ -- if it isn't going to
have its own build process it probably shouldn't live in another
location (especially if that makes the build scripts more convoluted).

This is a work in progress. I have tried to preserve the original tests
for the functionality of the bootstrapper, but they are broken at the
moment. It might be easiest to test with a mock "window" object.
Remove unnecessary bookmarklet build stuffs
Fix the bookmarklet tests

Some updates, migrations, changes:
- Use mocha, sinon, and chai
- Don't try to re-require, since modules are cached. Instead, just
require the bookmarklet once and take care of mocks and stubs to
make it re-usable.
- Kill support for having jQuery already loaded. That's nonsense and
`jQuery.sub()` has been removed in recent jQuery anyway. Just load it
always and use `noConflict()`.
- Change permissions -> annotateItPermissions where applicable
- The `<plugin>Options()` methods return the options object passed in,
not the one resulting from the plugin initialization. Therefore, don't
check for the class defaults to exist, such as `userId` on the
AnnotateItPermissions options.
Mock bookmarklet load more aggressively

Rather than trying to actually mock and test adding a script to the
DOM to load jQuery and annotator, just skip testing that bit and
mock `jQuery.getScript()` and the style modifications applied to the
head tag.
Remove redundant Make targets and includes

The dependency generation step in the main pkg/%.js rule has a sed
line that ensures the generated .d files are structured as rules
such that each only applies to the source files it strictly depends
on. As such, there's no need for a more complicated include at the
end than $(DEPDIR)/*.d to catch everything.

Also, the bootstrap script is caught by this because the bookmarklet
target depends on pkg/bootstrap.js.
Merge pull request #320 from okfn/bookmarklet-build

Reincorporate bookmarklet build