add SpatialPyramidPoolLayer c++ support

Fix previous ci error.

change the act.name for LinearActivation() to "linear" so that it won't fail in hl_activetype; also fix the hasinputsset in submodel

Add SumCost

'*' operator overload for LayerOutput

Making '*' support the multiplication between a scalar and LayerOutput

Also changing '+' to support adding between a vector and a scalar.

Change-Id: I7daf35590dc2b2f855a29d9ef43ac57979442e0f

Add bilinear interpolation layer

fail in hl_activetype; also fix the hasinputsset in submodel

* set mixedlayer output size according to input operator
* change from num_channel to num_channels for conv_operator (the old one is
really misleading because all the others are num_channels)

* also changed the arg name in projections.py

Fix matrix inverse  unittest to be more robust

rebase deconv implementation with develop branch and resolve conflicts with pull#218 commit 45c81a41