add $min_or_max and $display params to variation pricing functions
Show file title instead of count if set
Change filecount variable
removed not useful global variables
fixed braces standards
fixed reviews metabox visibility
fixed standards
removed "Trying to get property of non-object..." error on the edit review/comment page.
Only allow a fee to be added once
tooltips on variations not showing after using link all variations button Fixes #4366
Fixing method call in verify_nonce function
Downloadable File Fixes/Tweaks

* Hooked up new downloadable product permissions function to
completed/processing actions
* WC_Product::get_files() is used rather than the underlying
_downloadable_files meta directly
* $this is passed to downloadable product filters in WC_Product in place
of $this->id which doesn't does not afford you the particular variation
when a product variation is being used.
Add coupon code placeholder to cart template
Revert back to ob_end_clean to fix errors

ob_clean does not turn off output buffering as ob_end_clean does. On
some hosts ob_clean results in an error like: transfer closed with 3
bytes remaining to read. ob_end_clean fixes this.
Fix HTTP_X_FORWARDED_HOST notice
Merge pull request #4381 from ChuckMac/master

Fixing method call in verify_nonce function
Merge pull request #4406 from maxrice/master

Fix HTTP_X_FORWARDED_HOST notice
Merge pull request #4401 from toddlahman/master

Revert back to ob_end_clean to fix errors
Merge pull request #4386 from justinstern/master

Downloadable File Fixes/Tweaks
Merge pull request #4388 from niravmehta/master

Expiry date calculation based on order completion date