Approval Queue Plus 3.5.2

Minor bugfix to explicitly enforce admin permissions on admincp tools

Fixes a critical upgrade bug (doesn't apply to new installs), where certain columns didn't get created

• update permission phrase to make it clear where the permission comes from
• rename user agent table from xf_user_agent to xf_aqp_user_agent to comply with resource standards
• bugfix - gracefully handle case where user agent doesn't exist for user
• fix approval_item_user template modification for compatibility with XF 2.3