tests: tweak which hg versions run test-pull-after-strip
tests: fix test-merge and test-octopus
tests: remove hg 1.4.3 from make all-version-tests
tests: fix for hg 1.5.4
tests: update versions included in make all-version-tests
makefile: document all-version-tests intentions
help: add additional help topics
templatekw: add support for gitnode template keyword