Use CiviCRM standard first letter case "Select donation type" changes to "Select Donation Type"

See merge request !5

CIVICRM-2034 Use CiviCRM standard first letter case "Select donation type" changes to "Select Donation Type"

update recurringbuttons.civix.php file

See merge request extensions/recurringbuttons!3

To avoid php 7.4 deprecation warnings.

Added German language and strings for Weekly / Yearly.

See merge request extensions/recurringbuttons!2

#10 - fix default setting configured on the contribution page.

See merge request extensions/recurringbuttons!1

Set the correct value is is_recur is already checked (could have been done by a buildForm hook or form error)

Remove unused CSS file, avoid running hook twice if loading via snippet for payment processors (check for is_recur)

extensions/recurringbuttons#2 Instead of replacing is_recur, add a separate+synched radio buttons. Fixes incompatibility with Stripe 6.x