Improve C macro style

[beutlich]

This is the preferred style for larger macro declarations and has two advantages

• Declared local variables will be properly scoped variables then
• It is always safe to use a trailing semicolon when macro will be called. Currently it is inconsistent for the UNUSED and CALL... macros.

[beutlich]

Macro ASSERT_STATE seems odd to me:

• In fmi1Functions.c the parameter A is not used at all. And there is desired side-effect by declaring S.
• In fmi2Functions.c there is no such side-effect as S is a parameter.
• In fmi3Functions.c there again is desired side-effect by declaring S.

I would prefer if macros do not introduce variables in the outer scope instead.

[t-sommer]

@beutlich, can you please clean up the whitespace changes that are displayed in the diff?

[beutlich]

@beutlich, can you please clean up the whitespace changes that are displayed in the diff?

Done.

Please note, that EOL is inconsistent for the source files, which makes it harder to contribute. All model.c files have CRLF line endings, while all other C source or header files have LF. In Modelica Standard Library we explicitly set C and H files as text, see https://github.com/modelica/ModelicaStandardLibrary/blob/master/.gitattributes