add _valueFromString method & fix spacing issue (#5)
add _valueFromString method & fix spacing issue (#5)

* add UITextView+GDORichText.h to set associate object

* fix spacing issue & remove _sizeFromString method
lumouren009/GDOperation,lumouren009/GDOperation,goodow/GDOperation,goodow/GDOperation,lumouren009/GDOperation,h15945/GDOperation,goodow/GDOperation,h15945/GDOperation,goodow/GDOperation,h15945/GDOperation,lumouren009/GDOperation,h15945/GDOperation