MultiScaleOrderlessPoolingLayer

The plan is to implement the network architecture proposed in the paper[1] that [@bhack found out](https://github.com/BVLC/caffe/pull/308#issuecomment-47745676). 

I haven't read the paper thoroughly. But I believe it is worth reproducing as [Gong](http://www.unc.edu/~yunchao/) was a [co-author](http://arxiv.org/abs/1312.4894) of [Yangqing](http://www.eecs.berkeley.edu/~jiayq/) and they had similarly strong academic records and industry experiences.

[1] Y Gong, L Wang, R Guo, S Lazebnik. Multi-scale Orderless Pooling of Deep Convolutional Activation Features. arXiv preprint arXiv:1403.1840.