hgwebdir: read --webdir-conf as actual configuration to ui (issue1586)
This cleans up code and allows specification of values more globally. For
example, it's now possible to specify web.contact in webdir-conf for all
repositories without a specified contact set.
% initialize repository
adding a
% try hgweb request
0
1f424bb22ec05c3c6bc866b6e67efe43 page1