ETF does not support read, write and copy.
Thus vset implementations should not write as if ETF does.
Also set the actions read matrix when the combined matrix is set.
Fixes a segfault in the regrouping layer, which expects that the actions read matrix is always set.
add necessary assertions to prevent segfault.
correctly add necessary values for boolean type in mCRL2.
separate init domain and universe. Necessary for multi process.