Added Support for Informix Databases

Thanks to @carloscs for adding support for Informix Databases.

Initial Github Release

1. Some fixes in Oracle Metadata Reader: Get constraint type, Get Foreign Table Column Name
2. Fix Pascal Formatter. All Tests are passing again.
3. Add Inflector Rules on settings change.
4. Fix .hbm.xml mappings generations according NHibernate 3.3. specification
   4.1. Remove element from element.
   4.2. Fix foreign key columns in composite key
   4.3. Add columns only once
5. Fix code generations
   5.1. Improvements in foreign keys
   5.2. Improvements in GetHashCode method.