Add revlog.strip to truncate away revisions.
This updates the revlog data structures for index and nodemap in place
so the .d and .i files don't need to be reread after stripping away a revision.
#!/bin/sh
hg init
echo 123 > a
echo 123 > c
hg add a c
hg commit -m "first" -d "0 0" a c
echo 123 > b
echo %% should show b unknown
hg status
echo 12 > c
echo %% should show b unknown and c modified
hg status
hg add b
echo %% should show b added and c modified
hg status
hg rm a
echo %% should show a removed, b added and c modified
hg status
hg revert a
echo %% should show b added and c modified
hg status
hg revert b
echo %% should show b unknown and c modified
hg status
hg revert c
echo %% should show b unknown
hg status
echo %% should show a b and c
ls
true