Installation using Intel OneAPI about calculix-adapter

[davidscn]

@yagi was able to install the CalculiX-adapter using multi-threading:

The path to the spoolesMT library has to be added in the LIBS specification before the actual spooles library. Example:

SPOOLES_LIBS_MT = /path/to/SPOOLES.2.2/MT/src/spoolesMT.a
SPOOLES_LIBS = /path/to/SPOOLES.2.2/spooles.a


LIBS = \
$(SPOOLES_LIBS_MT) \
$(SPOOLES_LIBS) \
...

Specifying the SPOOLES_LIBS first lead to the linking issues described above (on discourse).

[boris-martin]

The CI script has always been reliant on libyaml-cpp-0.7.0, so I guess we should update the documentation to recommend building that one from source.

Now there are quite a few flags that might be optional: USE_MT, -fallow-argument-mismatch (for GCC >= 10) and this -no-for-main. Maybe we should update the doc with a list of useful flags instead of putting them (or not) by default and hoping for the best