* Add new test for Search/Replace to ensure serializd data isn't mangled...

...,

* Remove length check for strings to determine if the MYSQL version could be used. Instead just use PHP.
* Change some test verbiage for clarity.
* Refactor 'fast' and 'safe' to 'mysql' and 'php' in method and variable names
* Change the 'safe' flag to 'precise' to better explain its purpose.