Solver switching support & implementation of Nesterov's accelerated gradient and AdaGrad
restored vituals in solver.hpp
converted pointers to shared_ptr
fixed solver constructor in train_net.cpp
improved numerical stability for AdaGrad
bugfixes for AdaGrad
Added L1 regularization support for the weights
fixed caffe.proto after a mistaken rebase
Addressed Yangqing's comments
fixes after rebase
proto conflit, lint, and math_functions (compiler complaint)
added unit test for solvers and fixed solver bugs
cleanup caffe.proto
Merge Test{SGD,AdaGrad,Nesterov}Solver; they become subclasses of
TestGradientBasedSolver
Added sanity check for AdaGradSolver; added MNIST examples for solvers
lint
Re-added solver switch into the new caffe main excutable; fixed AdaGrad MNIST example
lint
hot fix for warning
mnist_autoencoder: always compute both cross-entropy loss and L2
(euclidean) error