reading matrices/vectors from file relies on exceptions and not on boolean returns. bugfix in determining file extensions (when no '.' is present).
idx_t has a clear() method, the invalidate() has a slight different meaning.
removed unnecessary files
link to LAPACK libraries
throws propper expection when matrix is singular
rhs vector is not "clear()ed" after solving, just "zeroed", to maintain consistency of system components
matrix handles exceptions better, just std::runtime_errors now (to make it easier to handle in scripting). no typeid fiddling at runtime.
GaussianElimination solving now works for multiple column b vector
output of matrix index corrected
execute call wraps solve in try-catch