Remove some code to reduce the size of the mobile inference library.

[hedaoyuan]

The code that removed from the mobile inference library:

1. SparseRowCpuMatrix
2. SparseMatrix
3. Remove some useless layers

[Xreki]

I have tested this PR in iOS app, the static libraries' size are reduced from

-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users   8663872 11 14 11:31 libpaddle_capi_engine.a
-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users  14365784 11 14 11:31 libpaddle_capi_layers.a
-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users  23029560 11 14 11:31 libpaddle_capi_whole.a

to

-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users   6863352 11 14 17:30 libpaddle_capi_engine.a
-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users  10040944 11 14 17:30 libpaddle_capi_layers.a
-rw-r--r--  1 liuyiqun01  INTERNAL\Domain Users  16904200 11 14 17:30 libpaddle_capi_whole.a