Fix the directory and revlog collision problem
This adds escaping for directory names so that directory foo.i doesn't
collide with the revision data for file foo.
+ hg init+ echo This is file a1+ hg add a+ hg commit -m 'commit #0' -d '0 0'+ lsa+ echo This is file b1+ hg add b+ hg commit -m 'commit #1' -d '0 0'+ hg co 0+ lsa