pretty the build with the Q variable

Unset Q (in the environment) to see full commands, or edit in
Makefile.config.
remove unused GetLayer function (replaced by LayerRegistry::CreateLayer)
Merge pull request #1645 from longjon/remove-get-layer

Remove unused GetLayer function (replaced by LayerRegistry::CreateLayer)
[scripts] fix find warnings in upload_model_to_gist.sh
Merge pull request #1561 from longjon/pretty-build

Pretty up the build
Merge pull request #1648 from longjon/find-warnings

Fix find warnings in upload_model_to_gist.sh
move softmax loss GPU todo comment to header file

There's no need to have GPU stubs just for a comment, and the absence of
a GPU-specific implementation is made more obvious by the nonexistence
of the .cu file.
Merge pull request #1655 from longjon/softmax-loss-todo

Move softmax loss GPU todo comment from .cu file to header file
remove SoftmaxLossLayer CPU_ONLY stubs, since there is no GPU version
Merge pull request #1656 from longjon/fix-softmax-loss-stubs

Fix an error made in removing the SoftmaxLossLayer GPU stubs
only build matcaffe as part of 'make everything' if MATLAB_DIR is set
don't do runtest as part of 'make everything'
Merge pull request #1658 from jeffdonahue/make-everything-tweaks

'make everything' tweaks
[tests] don't use Gaussian labels in NetTest's TinyNet

Previously, labels were being nonsensically filled with a zero-mean
Gaussian. Now they are just set to constant zero. Note that this is not
necessary for TrickyNet, neither forward nor backward are ever called.
Merge pull request #1661 from longjon/init-test-labels

Fix sketchy label initialization in NetTest
add BaseConvolutionLayer

This provides a common place for code used by ConvolutionLayer and
DeconvolutionLayer, simplifying the implementations of both.
add CPU_ONLY ifdef guards to BaseConvolutionLayer
rewrite ConvolutionLayer to use BaseConvolutionLayer helpers
add DeconvolutionLayer, using BaseConvolutionLayer