Support working with raw RSAPublicKey.

- Add methods to convert to/from ASN.1 RSAPublicKey only (not
  just SubjectPublicKeyInfo wrapper that is more common).
- Add methods to convert to/from PEM.
Allow non-array to be passed as headers option to create http request.
Fix typo.
Remove unnecessary dependencies.
Fix certificate chain when creating certificate message.

- Closes #39.
- Thanks @mstrum.
Add optional parsing strict mode to fromDer, defaults to true.
More appropriately name AES cipher functions.
Begin to better modularize tls cipher suites.
Update indentation, etc.
Move AES cipher suites into a separate module.
Rename initCipherParameters to initSecurityParameters.
Add TODOs.
Move MAC setup into external cipher suite module(s).
Upgrading jsbn to 1.3
Merge pull request #42 from KevBurnsJr/master

Upgrading jsbn to 1.3. Thanks @KevBurnsJr!
Update package description and keywords.
Package description update.
Use hardcoded .gitignore.

It's more common to just use the JS pieces of forge now so make it easy
on developers and hardcode the .gitignore entires.
Update to require Python 2.7.
Fix typos.