wireproto: config options to disable bundle1 bundle2 is the new and preferred wire protocol format. For various reasons, server operators may wish to force clients to use it. One reason is performance. If a repository is stored in generaldelta, the server must recompute deltas in order to produce the bundle1 changegroup. This can be extremely expensive. For mozilla-central, bundle generation typically takes a few minutes. However, generating a non-gd bundle from a generaldelta encoded mozilla-central requires over 30 minutes of CPU! If a large repository like mozilla-central were encoded in generaldelta and non-gd clients connected, they could easily flood a server by cloning. This patch gives server operators config knobs to control whether bundle1 is allowed for push and pull operations. The default is to support legacy bundle1 clients, making this patch backwards compatible.