Adds phone field

Similar to text field, uses phone pad keyboard
add Class registration to override type-based Field class selection when field type is default
Add FXFormOptionSegmentsCell, for short option lists.

Also added an example. The SegmentedControl will try to use the entire
cell width if the `FXFormFieldTitle` value is an empty string.
Add UITapGestureRecognizer to contentView instead of cell itself

This allows the add and delete buttons that are added by
`UITableViewCellEditingStyleInsert` and
`UITableViewCellEditingStyleDelete` to intercept touches.
Replaced the deprecated UITextAlignmentLeft with NSTextAlignmentLeft.
Merge pull request #85 from jlajlar/master

Replaced the deprecated UITextAlignmentLeft with NSTextAlignmentLeft.
Merge pull request #82 from bartvandendriessche/fix/add_tapgesturerecognizer_to_contentview

Add UITapGestureRecognizer to contentView instead of cell itself
add optionDescriptionAtIndex
Merge pull request #35 from boxer/phone-field

Adds phone field
Merge pull request #39 from sdesimone/master

add Class registration to override type-based Field class selection when field type is default
Updated to 1.2 beta
Merge branch 'master' of https://github.com/nicklockwood/FXForms
Added ability to register cell and controller classes based on field class
Merge pull request #55 from bartvandendriessche/feature/FXFormOptionSegmentsCell

Add FXFormOptionSegmentsCell, for short option lists.
Added FXFormOptionSegmentsCell
Added dynamic fields example
fix FXFormImagePickerCell image width miscalculation
Merge pull request #108 from heychenbin/master

fix FXFormImagePickerCell image width miscalculation
Code cleanup
Improved type inference for dynamic fields