hgweb: use a function expression for the install listener of followlines UI
We define the listener of document's "DOMContentLoaded" inline in registration
and use a function expression (anonymous) with everything inside. This makes
it clearer that this file is not a library of JavaScript functions but rather
an executable script.
(Most of changes consists of reindenting the "followlinesBox" function, so
mostly white space changes.)
#
# Avoid interference from actual test env:
unset HGTEST_JOBS
unset HGTEST_TIMEOUT
unset HGTEST_PORT
unset HGTEST_SHELL