rollback previous commit adding version number to NetParameter -- going
a different route
some post rebase fixes -- copyright, hdf5_output layer (still need to
incorporate into util/upgrade_proto)
cleaner version of refactoring with fields added to LayerConnection
(which retains an optional V0LayerParameter field for legacy support)
and LayerConnection renamed to LayerParameter
add support for hdf5 output layer
minor cleanup
fix upgrade_net_proto names
update docs (and a couple comments) for refactored layerparam
add NetParameterPrettyPrint so that upgrade tool prints inputs before
layers