v24 Support and GMatrix

[lukelowry]

Summary

• Added v24 .pwb files and updated the .pwd one-line files for cases.
• Added get_gmatrix() function to test v24 functionality.
• Improved readability of get_jacobian() :
  • Added private helper _parse_real_matrix() that is called by get_jacobian() and get_gmatrix(), to reduce bloat.
  • Partitioned by comments for readability
  • Added try/finally block for the temporary file management

Tests

• Added respective unit tests for get_gmatrix()
• Updated some seemingly outdated tests and removed one test that I believe is obsolete. Please review the minor modifications to the unit tests.

Please advise on any other chores required for a PR.