d1acc987e9
refactor the wildcard matching code to make it a bit easier to understand, in hopes that it will reduce the difficulty of converting from RBTDB to QPDB later. there are also some minor optimizations: previously, after stepping backward to find the predecessor, we stepped back foward *from* the predecessor to find the successor. we now reset the rbtnode chain to its original starting point before stepping forward; this eliminates some unnecessary processing. and, if neither predecessor nor successor is found, we return early rather than carrying on with an unnecessary effort to match labels.