reverting the reorganization done in 3455-3456 in order to make merging my experimental branch to trunk easier.

Preparation for new organization of code in to sub packages. Changed autoload() to work with new structure.

Refactorings for schema files and Doctrine_Record builder. More to come but got held up on some things that zYne- must fix first.

Consolidated a few things. Initial entry of Inflector class. Moved some methods from Doctrine base class to Doctrine_Lib and Doctrine_Inflector.

Fix array_merge so that schemas that are loaded after are merged in to the existing array of schemas.

initialized $columns in listTableColumns. it threw an undefined variable error if the table was missing or had no columns defined.

New fix for the check for duplicates between explicitly declared custom relations and autogenerated relations.

fixed code so those problems wont occure. However the method still not works as intended, 
more information see mail at doctrine-dev mailinglist.
Fixed same Problems in other drivers aswell.