util: check fileno() validity in win32 set_binary()

clone: print "updating working directory" status message With this change, "hg clone" looks like this: % hg clone http://example.com/repo/big big requesting all changes adding changesets adding manifests adding file changes added XXX changesets with XXX changes to XXX files updating working directory XXX files updated, XXX files merged, XXX files removed, XXX files unresolved So the user sees % hg clone http://example.com/repo/big big requesting all changes adding changesets adding manifests adding file changes added XXX changesets with XXX changes to XXX files updating working directory while Mercurial is writing to disk to populate the working directory With this change, "hg clone" looks like this: % hg clone big big-work updating working directory XXX files updated, XXX files merged, XXX files removed, XXX files unresolved

give better error message on non-existent mapfile (issue813)