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)

Added different counter query support for Doctrine_Pager. Now it can use 2 different queries to paginate items. Added 4 new methods: setCountQuery, getCountQuery, setCountQueryParams and getCountQueryParams. If not defined a counter Doctrine_Query, the collector one is used. If no params were defined to be used in counter query, the ones passed by execute method are used

Fixed count bug in Doctrine_Pager that was wrong counting the total of results found. Added 3 new methods: Doctrine_Pager::getExecuted (checks if the Pager was already executed), Doctrine_Pager_Layout::execute (handy access to execute Pager query without having to access Doctrine_Pager instance) and Doctrine_Pager_Layout::processPage (processes the template of a given page and returns the parsed string)