Vishakh H <vsh426@gmail.com> [Tue, 03 Aug 2010 19:38:19 +0530] rev 11745
revlog: add punched revision flag
index flag to identify a revision as punched, i.e. it contains no data.
REVIDX_PUNCHED_FLAG = 2, is used to mark a revision as punched.
REVIDX_KNOWN_FLAGS is the accumulation of all index flags.