Move RPC auth token from Authorization header to X-Gerrit-Auth

Servers that run with auth.type = HTTP or HTTP_LDAP are unable to
use the web UI because the Authorization code supplied by the UI
overrides the browser's native Authorization header and causes the
request to be blocked at the HTTP reverse proxy, before Gerrit even
sees the request.

Instead insert a unique token into X-Gerrit-Auth, leaving the HTTP
standard Authorization header unspecified and available for use in
HTTP reverse proxies.

Bug: issue 1743
Change-Id: Ice143405dc4d59ade56a6e4a385a4a0995e347ff
8 files changed