add data for gpi test
add Broadcast operation
add asDiagonal()
remove caching as it shouldnt be tested here
add Scalar::exp()
add mean and covariance functions for GPI
continue fixing GPI bugs
output parameters as well
add RowsAtCompileTime and ColsAtCompileTime

compilation problem
add simple test
add rows and columns to all classes
change is_convertible for is_base_of
rows and cols of input matrix are referred to as RowsAtCompileTime etc.