Remove references to supporting MySQL 5.1; clean up MySQL permissions

Created by: MegaphoneJon

Oops - pardon the whitespace stripping, my text editor did that automatically! The ACTUAL changes are:

• Changed MySQL minimum version to 5.5 from 5.1;
• MySQL permissions were identical for "5.1.6-5.7.6" and "5.7.6+" now, so I removed the duplicate;
• Moved CREATE VIEW into the list of required permissions instead of breaking it out into an, "If you use CiviCase" section.