Updated the installation routine for the CoolProp python package in the
LibreOffice wrapper to use pip. This simplifies the script, as the download
links for different platforms and ABI versions will be handled by pip.
Bundled Python interpreters in LibreOffice doesn't include pip. But as pip
itself is platform independent and runs on py2/py3, it will be bundled inside
the LibreOffice extension at build time.
* Make wrapper for LibreOffice an extension
The LibreOffice wrapper is changed to be a real extension for LibreOffice.
Just as with the current solution, Python is used for the calculations in
the background.
* The extension now contains the complete wrapper code. Thus, there is
no need anymore to use a special prepared LibreOffice template file.
* The wrapper is extended to contain all high-level interface functions
and includes descriptions for the cell formulas.
* The extension contains a helper function to download and install the
CoolProp Python package within the extension directory. This function
can be called from the LibreOffice options menu. On macOS the Python
certifi package will be used to verify certificates for https downloads.
* Update web documentation for new LibreOffice extension
* Installation and usage instructions
* Create CMake target for building of the LibreOffice wrapper
* Prepare and bundle all files as .oxt extension file
