To give better feedback to the user in the case of a typo in the project name, and to prevent invalid projects from being created, the validation of the project name for the GC import should do a HEAD request and confirm a 200 response.
Some example projects that fail:
sdcardrecovery2013: 403 (private)
tauroplay: 404 (typo?)
Closed #518.
je/42cc_6895