Adding some utility methods for dimension checking

The DimensionChecking utility class provides utility methods for
checking the dimensions of a matrix or a vector.  These methods will
throw a dimension exception if the conditions are not met.
Interface representation of a safe matrix

A SafeMatrix is a matrix that checks every command for any invalid
indexes or invalid matrix arguments.
Interface representation of a safe vector

A SafeVector is a vector and a safe matrix that checks every command for
any invalid indexes or invalid vector arguments.
Updating dimension exceptions

Adding vector dimension exception and updating matrix dimension
exception.