[fix] check solver prototxt parsing
Merge pull request #1226 from longjon/check-solver-prototxt

[fix] check solver prototxt parsing
[example] fix data script paths for flickr fine-tuning
[example] add LeNet to MNIST title, fix paths to be from root
[example] re-title LeNet / MNIST heading too
[docs] update homebrew instructions for boost and boost-python split
[docs] note boost 1.56 an CUDA conflict on OS X
Added Multistep, Poly and Sigmoid learning rate decay policies

Conflicts:
	include/caffe/solver.hpp
	src/caffe/proto/caffe.proto
	src/caffe/solver.cpp
[docs] pip install packages in order for dependencies
[docs] pip install harder
[examples] fix reference model name for flickr fine-tuning
Refactored leveldb and lmdb code.
Some cleanup to make travis happy.
Updated interface to make fewer string copies.
Don't autocommit on close for the databases.  If they were read-only, then they might fail.
data layer test was relying on the autocommit on close db behavior that was recently removed.
Updated cifar10 build script to specify db backend.
Switched create_cifar10.sh output from leveldb to lmdb.
Updated extract_features to take a leveldb/lmdb config option.
Updated Database interface to use custom KV type rather than std::pair.  Removed two buffer copies in dereference operation for DB iterators.