Fix AutocapitalizationType capitalization

Capitalization in AutocapitalizationType should not be capitalized.
Allow for IsSecure, KeyboardType, AutocapitalizationType and AutocorrectionType customizations

Pass the secure, keyboard, autocapitalization and autocorrection options on and overwirte the default values when set. This allows for more customized fields like:

bundle.text "E-mail",   key: "email",    keyboard: "EmailAddress", autocapitalization: "None"
bundle.text "Password", key: "password", secure: true
Merge pull request #4 from cimm/master

Extra configuration options for text fields