revlog: use raw revisions in clone test-revlog-raw.py now shows "clone test passed", but there is more to fix.

revlog: use raw revisions in revdiff See the added comment. revdiff is meant to output the raw delta that will be written to revlog. It should use raw. test-revlog-raw.py now shows "addgroupcopy test passed", but there is more to fix.

revlog: use raw content when building delta Using external content provided by flagprocessor when building revlog delta is wrong, because deltas are applied to raw contents in revlog. This patch fixes the above issue by adding "raw=True". test-revlog-raw.py now shows "local test passed", but there is more to fix.

revlog: fix _cache usage in revision() As documented at revlog.__init__, revlog._cache stores raw text. The current read and write usage of "_cache" in revlog.revision lacks of raw=True check. This patch fixes that by adding check about raw, and storing rawtext explicitly in _cache. Note: it may slow down cache hit code path when raw=False and flags=0. That performance issue will be fixed in a later patch. test-revlog-raw now points us to a new problem.

revlog: rename some "text"s to "rawtext" This makes code easier to understand. "_addrevision" is left untouched - it will be changed in a later patch.

revlog: clarify flagprocessor documentation The words "text", "newtext", "bool" could be confusing. Use explicit "text" or "rawtext" and document more about the "bool".