Merge branch 'js/misc-doc-fixes'

"make check-docs", "git help -a", etc. did not account for cases where a particular build may deliberately omit some subcommands, which has been corrected. * js/misc-doc-fixes: Turn `git serve` into a test helper test-tool: handle the `-C <directory>` option just like `git` check-docs: do not bother checking for legacy scripts' documentation docs: exclude documentation for commands that have been excluded check-docs: allow command-list.txt to contain excluded commands help -a: do not list commands that are excluded from the build Makefile: drop the NO_INSTALL variable remote-testgit: move it into the support directory for t5801