Fixes minor issues with ac/make process

[adcroft]

Where we had placed the dependency discovery (makedep) was leading to some small annoyances:

• The dependency generation was being invoked twice
• The dependency generation was not invoked when source code was changed.

Now:

• ./configure creates config.status Makefile and Makefile.dep
• ./config.status recreates Makefile and Makefile.dep
• make depend recreates Makefile.dep
• make will conditionally recreate Makefile.dep

Changes:

• Add dependency of Makefile.dep on source code in Makefile.in. This allows make to know when to run makedep.
• Fix syntax issue for AC_CONFIG_COMMANDS which caused errors to be issued without stopping.

Side note: the system works perfectly well if we comment out the "AC_CONFIG_COMMANDS" line in configure.ac to invoke makedep. This is because make now knows how

[codecov]

Codecov Report

Merging #174 (703622d) into dev/gfdl (c598441) will not change coverage.
The diff coverage is n/a.

❗ Current head 703622d differs from pull request most recent head c3e1755. Consider uploading reports for the commit c3e1755 to get more accurate results

@@            Coverage Diff            @@
##           dev/gfdl     #174   +/-   ##
=========================================
  Coverage     34.01%   34.01%           
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  Files           259      259           
  Lines         70289    70289           
  Branches      13021    13021           
=========================================
  Hits          23906    23906           
  Misses        41879    41879           
  Partials       4504     4504           

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[marshallward]

I still don't get why [Makefile.dep] cannot accept those [] delimiters, and I do wonder if makedep ought to pre-generate that source list, but this is a big improvement.