Wrapper view with UITextField. Similar to the textfields of Material Design. NMATextField has following advanced features:
- Enabling secured text entry with a trailing button to toggle visiblity of secured text
- Mandatory flag to validate input if it has at least 1 character and if not a corresponding error message will be displayed beneath the textfield
- Disabling textfield and a corresponding trailing lock image will be displayed
- NMANumericTextField subclass which allows only digits and even copy & paste of a text will be validated
- Enabling limitation of maximal number of characters in textfield




