add process id list to CPUBackend
rename: make_shared_blob -> reshape_blob
refactor for layers: sys -> backend
refactor: sys -> backend for layer unit tests
refactor: sys -> backend, the rest
refactor: sys -> backend for CUDA
remove System type
fix test script.
refactor: sys -> backend on GPU (remaining fix)
Merge branch 'master' into data-parallelism
rename unit test: shared-blob -> blob-reshape
API for making shared parameters
put param in registry instead of layer state
rename layer_registry to param_registry
fix GPU unit test
incomplete (and maybe incorrect) implementation of CPU data parallelism
remove parsolve
rm make_shared_blob and sdata calls
Merge pull request #13 from pluskid/data-parallelism

Merge incomplete Data parallelism (CPU)