Refactors StringUtilities

* Moves StringUtilites down to org.teiid.core.designer to allow more
  plugins to use it

* Converts StringConstants into an interface with StringUtilities
  implementing it and moving it string constants appropriately. This
  simplifies the need to those string constants throughout codebase
Reduces complexity and needless duplication

* There exists 2 ModelType classes, which both have identical values and
  literals. Reduce these down to a single class with the static constants
  refactored into a single enum

* **.util.ModelType
 * Adds enum Type which provides single point of information for all
   model types. All existing constants in rest of class defer to this enum
 * Existing constants remain to avoid too many code changes

* **.core.ModelType
 * Defers to the enum in the 'other' ModelType class Type enum.
 * Preserves all constants to avoid too many code changes
 * Discard unused isShredable function
 * Avoids adding a Type field to ModelType since this will not have been
   serialized in existing models

* StringUtilities
 * Provides CamelCase function

* IntermediateFormat
 * Removes another ModelType class and uses Type enum getCamelCaseName
   method instead
WIP Adds function for converting annotated translator classes into mxd files

* Takes a teiid annotated translator source file, reads the annotations
  and outputs an mxd xml file ready to be plugged into designer.