hgweb: move archive related attributes to requestcontext As part of this, "archive_specs" was renamed to "archivespecs" to align with naming conventions. "archive_specs" didn't technically need to be moved from hgweb. But it seemed to make sense to have all the archive code in the same class. As part of this, hgweb.configlist is no longer used, so it was deleted.

hgweb: move some config options to requestcontext Various config options from the repository were stored on the hgweb instance. While unlikely, there could be race conditions between a new request updating these values and an in-flight request seeing both old and new values, leading to weird results. We move some of options/attributes from hgweb to requestcontext. As part of this, we establish config* helpers on requestcontext. As part of the move, we changed int() casts to configint() calls. The int() usage likely predates the existence of configint(). We also removed config option updating from once every refresh to every request. I don't believe obtaining config options is expensive enough to warrant only doing when the repository has changed. The excessive use of object.__setattr__ is unfortunate. But it will eventually disappear once the proxy is no longer necessary.

hgweb: establish class for holding per request context Currently, hgweb applications have many instance variables holding mutated state. This is somewhat problematic because multiple threads may race accessing or changing this state. This patch starts a series that will add more thread safety to hgweb applications. It will do this by moving mutated state out of hgweb and into per-request instances of the newly established "requestcontext" class. Our new class currently behaves like a proxy to hgweb instances. This should change once all state is captured in it instead of hgweb. The effectiveness of this proxy is demonstrated by passing instances of it - not hgweb instances/self - to various functions.