Modified GetIndexVal method

Added an additional parameter to differentiate between row and column major arrays. If set to 0 , the layout is assumed to be row major and it is column major other wise.
The parameter is 0 by default.
negativeIndex code generator modified

Modified the code generator to add a new parameter for the array layout.
Modified negative index handler

Modified the specialised code generator. There is no need to generate  the layout value in case of a single index.
Modified matrixOpsPy

Removed uncessary comments.
Added a zeros_float.