w3adc: Update to allow multiple switches on single line

[ukmo-ccbunney]

There are several cases in the WW3 code base where it would be advantageous for the pre-processor (w3adc) to allow multiple switches on one line. I.e. to only include a line of code if all switches for that line are specified in the switch file.

This change updates w3adc.f to handle multiple switches on a single line both in the include files (if any) and the primary source file.

Each switch should start with the usual !/ and be chained together with no spaces between, or optionally an extra /, e.g. the following lines are equivalent and will only be activated if both the OMPH and T1 switches are set in the switch file:

    !/OMPH!/T1     <some code>
    !/OMPH/!/T1/   <some code>

The switch section is assumed to be complete when no more !/ characters can be read (or !/ is followed by a space).

Any amount of switches can be added to a line (up to the maximum line length of 143 characters defined in w3adc).

[ukmo-ccbunney]

Regression matrix test results will follow shortly.

[ajhenrique]

Changes proposed were discussed in a separate cover. They will be merged to the BF_omp_b4b branch and tested as part of the changes proposed in that branch, becoming part of the PR made to NOAA-EMC/WW3 repo and its review process. In this context, I will rerun selected OMP and MPI+OMP hybrid regression tests to verify changes proposed presently.

[ukmo-ccbunney]

For completeness here are the results of regtest matrix. Everything identical except the usual mww3_test_03 culprits.

matrixCompSummary.zip