- unified getDefaultFieldDeclaration(), force DEFAULT NULL when no default is set and the field allows nulls

- added support for temporary tables, tweaked createSequence and enum support in getDefaultFieldDeclaration()

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.

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Reverted changes for disabling foreign key sql exporting. Not needed since it can be done with attributes.

Again... Prevent quoting two times the table name, bug report by g00fy on irc, seems like this bug could be on other drivers as well