Update README.md

Include additional things we've done recently but haven't documented (UMD module loading, npm/bower, Buffer rewrite).
Update README.md

Fix some typos
Test for Filer as AMD module use in require.js with Buffer, regression issue 225
Make browser-request happy and provide a global shim for XHR in issue225 test
Add link to issue
Merge pull request #226 from humphd/requirejs-test

Requirejs test - Going to land this so we don't regress. @modeswitch FYI in case you want to back it out, but since you're so busy I want to press ahead, and this is pretty low risk.
Fix bower old version
v0.0.14