Tower 2.3.3

Expanding a folder in a commit's "Tree" list presented a white view on some setups. This is now fixed. Resolved an issue where GitLab and Bitbucket users would not see projects they had been invited to. Made the "History" view more robust by better dealing with invalid & unknown Git ref types. Scrolling position in Diffs is now properly reset in all cases when a new diff is loaded. Repository "Settings" screen now reflects changes to "description" value instantly. Date format for commit and stash items is now unified. Resolved an issue with the "Keep working tree" option when deleting a submodule. Resolved an issue where the "Working Copy" status was not reloaded after "Apply Stash" failed (e.g. due to a merge conflict) Simplified username validation for GitLab CE/EE account creation/updating; this resolves an issue where some users need email addresses as usernames for their authentication service.