This patch updates the shell scripts with some of the common best
practices, which should make them more resilient to unusual failures and
unexpected environments (in particular, directories with spaces).
Most of these were identified by shellcheck.
When regenerating the manpages, the mtime of the pod files is used.
That mtime can change based on file and repository manipulations,
because git does not preserve mtimes.
This causes unnecessary regenerations which require manual cleanups in
order to avoid cluttering the history unnecessarily.
This patch makes the generate script set the mtime of the pod files to
the time of the last git commit that affected them, if they have not
changed since. This avoids unnecessary changes and makes the script
easier to use.
There's one file that needed adjustment to match its last commit time,
that is also included here.
This patch adds man pages for chasquid's main commands and
configuration. They are generated using pod2man (commonly used for this,
and included with perl in most distributions).
The generated man pages are included to avoid introducing a dependency
for such simple task, similar to how we handle protocol buffer generated
files.
