Update print_variable functions and test_output files to comply with printf output.

[robgpita]

Proposed changes

This PR closes #32. The print_state() function is outputting non-standard scientific notation, and incompatible with standards used by other languages (C, C++, Julia) and other printf based I/O.

Fortran is the outlier in how scientific notation is expressed. The current output makes it very difficult for others to use baselines for testing.

The write statements in the print_3d_variable & print_2d_variable functions have been changed, and all of the files within the ref/test/test_output directory have been altered to reflect the new scientific notation necessary to comply with future testing of the kernel.

Types of changes

What types of changes does your code introduce?

• Bugfix (Change which fixes an issue)
• New feature (Change which adds functionality)
• Enhancement to existing functionality (non-breaking change which improves existing code or documentation)
• Breaking change (fix or feature that changes results and requires updates to test baselines)
• Documentation Update

Checklist

• I have read the CONTRIBUTING document
• I have ensured all my changes contribute to a common purpose
• I have verified my change does not add debug code
• I have verified my change does not add code that is commented out
• I have verified unit tests pass locally with my changes
• I have verified my changes adhere to style guidelines
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[middlecoff]

Looks good.

[LyndStringer]

At a minimum, we need to talk about the 11 to 12 digits change. We have already throttled back the fused multiply-adds to keep 11 digits. Again, 12 digits will be troublesome.

[LyndStringer]

Looks good!