R1:6aa006b90362

Make conduit-uri info easier to be copied into arcrc

Summary:
add the conduit URI and the username together with the arc
certificate to the setting page.

Test Plan:
run arc diff to make sure it still works after copying the
generated test into the .arcrc file.

Reviewed By: epriestley
Reviewers: epriestley
CC: epriestley
Differential Revision: 73