tests: unify the last sh tests
This requires a slightly smarter check-code check for sed output filtering.
tests: run most check-code sh checks on continued lines too
Some false errors are degraded to warnings and whitelisted.
revlog: speed up prefix matching against nodes
The radix tree already contains all the information we need to
determine whether a short string is an unambiguous node identifier.
We now make use of this information.
In a kernel tree, this improves the performance of
"hg log -q -r
24bf01de75" from 0.27 seconds to 0.06.