Improve string replacements

[mattbucci]

Closes

• https://github.com/PostgreSQL-For-Wordpress/postgresql-for-wordpress/issues/84
• https://github.com/PostgreSQL-For-Wordpress/postgresql-for-wordpress/issues/85
• https://github.com/PostgreSQL-For-Wordpress/postgresql-for-wordpress/issues/77

[mattbucci]

going to install some of the plugins listed as not working and see if I can find other reported issues before merging this.

I'd like to hopefully close https://github.com/PostgreSQL-For-Wordpress/postgresql-for-wordpress/issues/14 as well, they don't provide the exact SQL which was causing the problem but they do describe it had to do with comment counts

[mattbucci]

Need to handle https://github.com/PostgreSQL-For-Wordpress/postgresql-for-wordpress/issues/77 as well