Merge branch 'import_presale_keys' of https://github.com/Gustav-Simonsson/go-ethereum into Gustav-Simonsson-import_presale_keys

Conflicts:
	crypto/crypto.go

* Browser now has tabs
* Fixed a callback issue

* ImportPreSaleKey takes a KeyStore, a presale key JSON (e.g. file content)
  and a password string. It stores the key in the given key store.
* Refactored common AES decryption and moved some functions to crypto.go

Off of jsonWrapper

KeyStore (Low level key functionality)