xF2 Add-on Hide Poll Results 2.2.1

• Fix XF2.2+ creating thread with poll did not save the hide poll resulting settings

• Fix uninstaller not removing columns added by this add-on
• Requires php 7.0+
• Now depends on Standard Library by Xon
• Supports XF2.2

• Require XF2.1+
• Rename phrases & templates to match add-on standards
• Minor code cleanup

• Fix php 5.6 compatibility when opcache is disabled