docker-debian-jessie: fix errant mkdir

makefile: rename debian-jessie to deb `make debian-jessie` was a poor name choice on my part, because it really builds a package for the current debian platform, whatever that happens to be, rather than a specific platform. Rename it to just `make deb` so that it's a little clearer. As a result, it now places built debs in a "debian-unknown" directory.

run-tests: ignore failed removal of nonexistent installerrs When running tests with -j100 or so on a large machine, I see this os.remove call failing semi-regularly. Since it's not really a problem when the file is already gone, just suppress the error in that case.

templater: move verbosity-to-template matcher to constructor We're going to reuse this and it's silly for it to be done per-cset anyway.

templater: remove pseudo-ternary

templater: fix variable name that shadows built-in

templater: minor whitespace tweaks

lock: make trylock private

lock: loop a finite number of times in trylock (issue4787) ..before falling back to lock, which will sleep. This only addresses the CPU consumption of the reported issue.

reachableroots: silence warning of implicit integer narrowing issued by clang Tested with CFLAGS=-Wshorten-64-to-32 CC=clang which is the default of Mac OS X. Because a valid revnum shouldn't exceed INT_MAX, we don't need long width for large tovisit array.