need better tests for parse_args_mod

[nancycollins]

the developer_tests/utilities directory has a parse_args_test.f90 file, and the work directory has a parse_args_test.in input file. however, the test program never runs the second part of the test (testing name=value pairs) because control-d ends not only the first part of the test but the second part as well.

recommend there be a reserved keyword (e.g. quit) to end each section.

the test input file has only a few simple lines and does not test escape characters. it does test double quoted strings with embedded white space but not single quotes. it also has no tests for name=value pairs. it does not test very long lines or blank lines, or mismatched quotes (e.g. only an opening quote).

[hkershaw-brown]

see issue #219 for some discussion.

[hkershaw-brown]

closing inactivity