[TIMOB-32] API - Add support for displaying different keyboards

While we're here, here's the traits that both textfield (UITextField) and textarea (UITextView) have:

Autocapitilization: None, Autoshift for beginning of words, Autoshift for beginning of sentences, Autoshift for all chars

Autocorrection: Default, No, and Yes.

KeyboardType: Default, ASCII, Numbers and Punctuation, URL (with space bar replaced by ., /, and .com), Number pad, Phone pad, and Email address.

KeyboardAppearance: Default, Alert (rarely used)

ReturnKeyType: Default (Return), Go, Google, Join, Next, Route, Search, Send, Yahoo, Done, Emergency Call

EnablesReturnKeyAutomatically: Boolean; if yes, the return key will be disabled if and only if the text field is empty.

SecureTextEntry: Boolean; if yes, treated as a password field

Further properties for consideration wrt UITextField and UITextView:

Text Alignment: Left, center, right

Font: Font, with float size and family name. Instead of family name, it can be system font, bold system font, and italic system font.

Editable: Boolean. Native property on UITextView, can be done through delegate methods on UITextField.

UITextField-specific:

Placeholder: Grey text that shows up when the field is empty

Clears On Begin Editing: Boolean

Adjusts Font Size To Fit Width: Boolean

Minimum FontSize: float

Border Style: None, line, bezel, rounded rect (Like search)

Background Image: Stretchable image, replaces border style

Disabled background image: Stretchable image, used only if background image is defined

Clear Button mode: when to show the clear button "(x)" (Never, while editing, unless editing, always)

Left View: UIView (Button) on the left side to embed, such as a magnifying glass

Left View Mode: When the left view will be visible (Never, while editing, unless editing, always)

Right View: UIView (Button) on the right side to embed, such as a bookmarks button

Right View Mode: When the right view will be visible (Never, while editing, unless editing, always)

resolved in 0.5