Checkboxes lost it's status if error occurred (e.g. invalid handle) when adding a new page type, now checkboxes are able to remains checked after error.
Normalize description of view_page_in_sitemap key

The description of the view_page_in_sitemap defined in version_562.php
and the one defined in permissions.xml should be the same.
Fix mysql Exception Shown on Page Type Add

Fix mysql exception show on attempted duplicate page type handle
addition.

- Check for existing page type by handle and return error if found
Remove Variable Variables

Remove Variable Variables

Difficult to understand and servers no actual purpose here.
Fix type PermissionKey::add()

Fix type PermissionKey::add()

- Change `$$pkHasCustomClass` to `$pkHasCustomClass`
Format contains string commit

Format contains string commit for concrete5 coding standards

Commit 90a7e73f8f13f7c3aa0e9e8718e88e71f6f5b9de
Merge branch 'fix/page-type-add/checkbox-states-disappears-if-error-occurred' of https://github.com/ojalehto/concrete5 into merge_preserve_checkboxes_new_page_type_valdiation_error
Add is_array check

Add is_array check for `$_POST['akID']` to prevent any possible edge
case where that returned an int etc
Merge pull request #1310 from mkly/merge_preserve_checkboxes_new_page_type_valdiation_error

Merge preserve checkboxes new page type valdiation error
Merge pull request #1309 from mkly/format_contains_string_commit

Format contains string commit
Merge pull request #1307 from mkly/double_dollar_signs

Remove Variable Variables
Merge pull request #1304 from mkly/fix_mysql_error_on_page_type_duplicate_add

Fix mysql Exception Shown on Page Type Add
Merge pull request #1308 from mkly/fix_permissions_key_add_typo

Fix type PermissionKey::add()
Merge pull request #1301 from mlocati/patch-4

Normalize description of view_page_in_sitemap key