(next_signature): ...this to avoid conflicts with sign.c.
* gpg.h: Ditto.
* cvs.h (trace): Move decl...
* server.h (trace): ...here.
* main.c (trace): Move global...
* server.c (trace): ...here.
(serve_signature): s/read_signature/next_signature/.
* sign.c (get_signature): Verify signature when configured to.
* verify.c (iget_verify_checkouts, get_verify_checkouts): Use global
server_support.
(verify_state_to_string): New function.
(iget_verify_commits): Allow tracing of state.
(iverify_signature): Handle sig in a buffer.
(verify_signature): New function.
(verify_fileproc): Use new iverify_signature API.
* verify.h (get_verify_checkouts): Update proto.
(get_verify_commits, verify_signature): New protos.