Moved some vertcat/horzcat simplification logic to mx_tools.cpp
Made MXNode::getHorzcat, MXNode::getVertcat virtual member functions allowing specialization
Made MXNode::getHorzsplit, MXNode::getVertsplit virtual
Moved and generalized vertcat/horzcat of MX constants
Refactored MXNode::getHorzcat, MXNode::getVertcat for speed and maintainability
Fixed whitespaces/indentation in multiple_output.*pp
Allowed specialization of MXNode::getHorzcat, MXNode::getVertcat for MX atomics with multiple outputs
Moved vertcat(vertsplit), horzcat(horzsplit) simplification to split.cpp
Refactored Vertsplit::getVertcat, Horzsplit::getHorzcat