Fixes #2953.

Allows result sets to be iterated over without running out of memory on
large data sets.

I am also of the opinion that the resource type checks are unhappy. We depend on driver internals.

* removed "charset" patch
* implemeted resource_type compare with in_array instead of regex
* implemented functional tests for connection and statement.

if $persistent=false, resource_type == 'SQLAnywhere connection'