Trim or possibly remove library patch files

[casella]

The ​OMLibraries sub-project contains several patch files to adapt shipped libraries to OMC. These patches are provided to serve two purposes

• fix language non-conformities, that OMC does not accept, and that were put there by library authors using Modelica tools that do not enforce the standard rigorously
• work around OMC current limitations

Patches are, well, patches: they serve their purpose, but they are not nice to see, and they require maintenance every time the source library is changed in those parts which are affected. Also, very importantly, they create problems for library developers, that cannot use the patched libraries shipped with OMC, but rather use the source code of the GIT repo directly.

For the first purpose, the proper solution is to fix the library source code (e.g. by submitting pull requests on GitHub). For the second purpose, the proper solution is to improve OMC so that the limitations are overcome.

It is also well possible that some of those patches are no longer needed.

For release 1.14.0, I would suggest that we tentatively try to remove them during the development process, run the entire testsuite, analyze the regressions, and then try as much as possible to solve the issues in the proper way once and for all. Only for those cases that are demonstrated to still be critical, we could reintroduce them as an interim solution.