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
set -e
mkdir test
cd test
echo foo>foo
hg init
hg addremove
hg commit -m "1"
hg verify
hg clone . ../branch
cd ../branch
hg co
echo bar>>foo
hg commit -m "2"
cd ../test
hg pull ../branch
hg verify
hg co
cat foo
hg manifest