hgwebdir: allow a repository to be hosted at "/" This can be useful in general, but will also be useful for hosting subrepos, with the main repo at /.

httppeer: eliminate decompressresponse() proxy Now that the response instance itself is wrapped with error handling, we no longer need this code. This code became dead with the previous patch because the added code catches HTTPException and re-raises as something else.

httppeer: wrap HTTPResponse.read() globally There were a handful of places in the code where HTTPResponse.read() was called with no explicit error handling or with inconsistent error handling. In order to eliminate this class of bug, we globally swap out HTTPResponse.read() with a unified error handler. I initially attempted to fix all call sites. However, after going down that rabbit hole, I figured it was best to just change read() to do what we want. This appears to be a worthwhile change, as the tests demonstrate many of our uncaught exceptions go away. To better represent this class of failure, we introduce a new error type. The main benefit over IOError is it can hold a hint. I'm receptive to tweaking its name or inheritance.