Some git repos have a different ssh url scheme than github and we should
support them.
This change updates our regex format to account for repos that don't
start with "git", but are still valid ssh urls.
Also I added some tests to account for the various formats and to ensure
we don't show the public key when using https urls.
See: https://meta.discourse.org/t/182668
Installing multiple copies of the same theme/component is possible, but you rarely need to actually have multiple copies installed. We've seen many times new admins installing duplicates of components because they were unaware it was already installed. This PR makes the theme installer modal loop through the existing themes when you click on 'install', and if there is a theme with a URL that matches the URL you entered, a warning will show up and you will need to click 'install' again to proceed.
Penar Musaraj
Blake Erickson
Osama Sayegh
Roman Rizzi
Robin Ward