Refactor mkoptions (#1631)

Refactor mkoptions (#1631)

This commit refactors code generation for options. It uses a new configuration format for defining options (*.toml) and a new Python script mkoptions.py to generate the source code and option documentation.

The option behavior did not change for most of the options, except that for bool --enable-/--disable- long options enable/disable was removed. E.g. --enable-miplib-trick and --disable-miplib-trick got changed to --miplib-trick and --no-miplib-trick.

This commit fixes also an issues with set-option/get-option via the SMT2 interface. Before long options were only accessible if the name included the =ARG part.