Fixes

• Fatal error triggered by the Donor Dashboard on PHP 5.6
• Donations to Revenue table migration where migration got stuck on error
• Broken email tag link in description
• Cleared up PHP notices on system info page
• GiveWP Database management tool is now backwards compatible to MySQL 5.5
• Cleaned up extra .git directories that got included in vendors
• Donor search no longer shows undefined index notice
• Fatal error thrown on page/post edit screens when migration table creation failed
• Donor Dashboard now works properly on hosts with aggressive page caching
• Donor Dashboard is only generated by admins in the admin-side, not other users by accident