…ed in convert_mnist_data.cpp to lmdb

…ated description

fix for tools/extra/parse_log.sh

convert MNIST demo to lmdb, fixes

Clean up pycaffe core

…radient and AdaGrad

TestGradientBasedSolver

…ad MNIST example

(euclidean) error

test_iter (should be 100 instead of 50)

Note that we are dropping some checks from LRN layer. However, these
checks are fairly redundant; something is very wrong if these layers
are producing top blobs that are different sizes than their inputs, and
tests are the right place to catch that. The thing that really should be
checked (that isn't) is that that local_size needs to be odd; this will
be added in a future commit.

Strictly speaking, Reshape doesn't need to be called until the first
Forward call; however, much existing code (especially tests) assumes
that top blobs will be set up in SetUp, so we may as well do it there.

Now that top blobs are set up in Layer::Reshape, it's Reshape that is
mandatory, and simple layers often don't need to implement LayerSetUp.
Reshape is (already) declared abstract, so not implementing it is a
compile-time error.

Since we are now calling Reshape in the Forward pass, it's only fair to
include it when timing. Reshape calls should normally be four or so
orders of magnitude faster than Forward calls; this change also makes it
easy to notice a mistake that causes something slow to happen in
Reshape.

Note that it is not normally necessary to call this function when using
reshapable nets, but sometimes it can be useful to compute the sizes of
intermediate layers without waiting for the forward pass.

…ires

On-the-fly net resizing, without reallocation (where possible)

  [model zoo] download gist script

- invoke by shell
- default download dir to models/
- save to flat dir of owner-gist instead of nested owner/gist

  Add contrastive loss layer, tests, and a siamese network example