revlog: move part of "addrevision" to "addrawrevision" "addrawrevision" will be the public API to reuse revision rawdata elsewhere. It will be used by a future patch.

filectx: add an overlayfilectx class The end goal is to make it possible to avoid potential expensive fctx.data() when unnecessary. While memctx is useful for creating new file contexts, there are many cases where we could reuse an existing raw file revision (amend, histedit, rebase, process a revision constructed by a remote peer, etc). The overlayfilectx class is made to support such reuse cases. Together with a later patch, hash calculation and expensive flag processor could be avoided.

filectx: remove __new__ It does not seem to be used anywhere, and breaks a later patch.

filectx: add a rawflags method The new method returns the low-level revlog flag. We already have "rawdata" so a "rawflags" makes sense. Both "rawflags" and "rawdata" will be used in a later patch.

filectx: move size to basefilectx See previous patch for context - avoid code duplication.

filectx: make renamed a property cache See previous patch for context - mainly to avoid code duplication.

filectx: make flags a property cache Make basefilectx._flags a property cache, so basefilectx.flags() could be reasonably reused. This avoids code duplication between memfilectx and a class added in a later patch.

commandserver: move printbanner logic to bindsocket bindsocket now handles listen automatically. "printbanner" seems to be just a part of "bindsocket". This simplifies the interface a bit.