fixes #689, which details problems with the handling of MySQL native enum columns and model class generation.

fixes #696 function was named synchronizeWithArray but i renamed it to synchronizeFromArray because it makes more sense because all the other mades user the term "from"

- LIMIT and OFFSET clauses allow only integers now
- Added support for INDEX BY
- Added more tests, fixed failing tests, etc.

Added Doctrine::HYDRATE_NONE example to "Fetch Only What You Need" subchapter of the "Improving performanc" chapter.

Removed initial definition of setSelectedTemplate in Doctrine_Pager_layout in all branches. If no selected template is defined, the default assigned template is used. This prevent possible issue where the user defines default but not selected template (will use the defined one in class, what is wrong)