Fix style in updater.js

- Use === for comparison instead of ==
- Refactored update(..., ...) function: already defined parameter 'update'
  changed to 'updates'
Add jsrsasign library to bower

- Adapted browserify to shim jsrsasign
- Gruntfile changed
Fix style in storage.js

- Variable declarations moved to beginning of functions
Add crypto.js module

- sha1 function: Generates the SHA1 hash of a message
- verify function: Verifies a signatures over a message
  and a certificate