Revert "Added support of MEDIUM- and LONG text and blob types in MySQL"
Revert "Added support of MEDIUM- and LONG text and blob types in MySQL"

Part of the fix for issue #752.
This reverts commit 6b4069b1fb21e8ed65c92dd8c494760385c16cbc.

creichert/persistent,bitemyapp/persistent,naushadh/persistent,gbwey/persistent,psibi/persistent,yesodweb/persistent,gbwey/persistent,gbwey/persistent,paul-rouse/persistent,plow-technologies/persistent,erikd/persistent