Bump to RC version

Bump version to 8.1.5

v8: Add umbLoader directive (umbraco#4987)

(cherry picked from commit e4f19f7)

Bump version to 7.15.3

Bump version to 8.1.3

Bump version to 7.15.2

Sorting of images in multiple media picker

(cherry picked from commit ed5effd)

Revert "V8: Don't show multiple open menus (take two) (umbraco#5609)"

This reverts commit 9ce996c.

(cherry picked from commit 1d49c86)

Merge pull request umbraco#5951 from umbraco/v7/hotfix/5921-preview-f…

…ailing

umbraco#5921 - AB#1794 - Remove…

Merge pull request umbraco#5798 from kjac/v8-fix-save-member

V8: Can't save members without resetting their password