wireproto: formalize permissions checking as part of protocol interface Per the inline comment desiring to formalize permissions checking in the protocol interface, we do that. I'm not convinced this is the best way to go about things. I would love for there to e.g. be a better exception for denoting permissions problems. But it does feel strictly better than snipping attributes on the proto instance. Differential Revision: https://phab.mercurial-scm.org/D2719

wireproto: declare permissions requirements in @wireprotocommand (API) With the security patches from 4.5.2 merged into default, we now have a per-command attribute defining what permissions are needed to run that command. We now have a richer @wireprotocommand that can be extended to record additional command metadata. So we port the permissions mechanism to be based on @wireprotocommand. .. api:: hgweb_mod.perms and wireproto.permissions have been removed. Wire protocol commands should declare their required permissions in the @wireprotocommand decorator. Differential Revision: https://phab.mercurial-scm.org/D2718

wireprotoserver: check permissions in main dispatch function The permissions checking code merged from stable is out of place in the refactored hgweb_mod module. This commit moves the main call to wireprotoserver. We still have some lingering code in hgweb_mod. This will get addressed later. Differential Revision: https://phab.mercurial-scm.org/D2717

wireprotoserver: check if command available before calling it The previous behavior was just plain wrong. I have no clue how it landed. My guess is a merge conflict resolution gone wrong on my end a few weeks ago. Differential Revision: https://phab.mercurial-scm.org/D2716

py3: drop encoding.strio() Its buffered nature makes TextIOWrapper unsuitable for temporarily wrapping bytes I/O.

ui: adjust Windows workaround to new _readline() code It's only needed when rawinput() is called. Also made it Py3 compatible.