revlog: drop silly `raw` parameter to `rawdata` function This is a leftover from `revision` and does not make sense for `rawdata`

perf: don't depend on pycompat for older Mercurial versions We already define local _sysstr() and _xrange() for compatibility, so we should use those. Also create a similar local _bytestr() corresponding to pycompat.bytestr(). Differential Revision: https://phab.mercurial-scm.org/D6745

perf: don't try to call `util.queue` on Mercurial version before it existed Differential Revision: https://phab.mercurial-scm.org/D6744

perf: handle NameError for `pycompat.foo` when pycompat wasn't imported On old Mercurial versions, we won't have a pycompat variable defined, and then `pycompat.foo` will raise a NameError. Differential Revision: https://phab.mercurial-scm.org/D6743

rawdata: update callers in shallowbundle We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.

rawdata: update callers in storageutils We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.

rawdata: update callers in delta utils We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.

rawdata: update callers in repository We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.

rawdata: update callers in testing/storage.py We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.

rawdata: update callers in test-revlog-raw We update callers incrementally because this help bisecting failures. This was useful during development, so we expect it might be useful again in the future.