tests/test-check-jshint.t

hgweb: don't call sys.exit() in httpservice.run()

If I'm reading the code correctly, `mercurial.server.createservice()`
can return an hgweb service or one of three types of command server
services. The caller then calls `mercurial.server.runservice()`,
passing it the returned service's run method. Only the hgweb service
was calling `sys.exit()`. It has been that way since 8d44649df03b
(refactor ssh server., 2006-06-04). That commit message doesn't
provide any explanation. Let's clean up and have the code follow the
usual return path into the `dispatch` module.

After this patch, there should be no remaining places left where we
call `sys.exit()` except for valid uses in the `dispatch` and `worker`
modules.

Differential Revision: https://phab.mercurial-scm.org/D9272

#require test-repo jshint hg10

  $ . "$TESTDIR/helpers-testrepo.sh"

run jshint on all tracked files ending in .js except vendored dependencies

  $ cd "`dirname "$TESTDIR"`"

  $ testrepohg locate 'set:**.js' \
  > 2>/dev/null \
  > | xargs jshint