Allow filtering of From Name and Email Address

We would like to be able to filter the from name and email address for different product groups.
Fixed an AJAX tax bug

Probably caused by 7096294ccebb4cbd09365644ebc573991242bdf6

Taxes are calculated by ‘billing_country’ so all country vars that
influence tax calculation should be named ‘billing_country’
Small code style change
Merge pull request #2024 from jdevalk/patch-2

Allow filtering of From Name and Email Address
Merge pull request #2025 from barrykooij/bug/ajax-tax-bug

Fixed an AJAX tax bug
Merge pull request #2023 from cklosowski/master

Add sanity checks to item being added to cart
First Pass at Inline Documentation for EDD Filters

includes\class-edd-api.php
Minor spelling error
Merge pull request #2030 from NikV/master

First Pass at Inline Documentation for EDD Filters
only validate IPN when it's enabled. Closes #2032
remove echo test. #2032
Actually pass backtrace to trigger_error(). Avoids just being presented with an error saying "1"
Merge pull request #2034 from leewillis77/print_r_fix

Actually pass backtrace to trigger_error().
Merge pull request #2029 from ghost1227/issue/1988

Minor spelling error
don't prevent sessions in admin. #2031
Update column 'download' to use singular label
Merge pull request #2039 from elliott-stocks/patch-10

Update column 'download' to use singular label
Account for UPLOADS constant in process-download.php. #2041
Merge branch 'master' of github.com:easydigitaldownloads/Easy-Digital-Downloads
Add https support to get_option('siteurl')