Fix revlog-ng interaction with old-http.
revlog.py wasn't trying to detect the version of a revlog file that
doesn't exist on the filesystem (as is the case with old-http).
Additionally, there was an off-by-one error in httprangereader.read
(ranges in HTTP Range headers are inclusive), making it get more data
than what was asked for. This made a struct.unpack complain that
"unpack str size does not match format".
Finally, with the two fixes above, test-static-http fails, since
BaseHTTPServer doesn't understand ranges and returns too much data.
Work around that by reading only the specified amount.
#!/usr/bin/env python
#
# An example CGI script to use hgweb, edit as necessary
import cgitb, os, sys
cgitb.enable()
# sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
from mercurial import hgweb
h = hgweb.hgweb("/path/to/repo", "repository name")
h.run()