[ Graph ] Neural Network Graph

[ Graph ] Neural Network Graph

In this PR, NetworkGraph Class is introduced and compile method is
implemented.
During the compile process, it takes layers vector which is created by
model_loader and create required layers like Activation, Flatten,
Concat or Addition Layers. Also it modify inputs relatively and
Calculate the order of calculation. So far, only serial processing is
supported.

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: jijoong.moon <jijoong.moon@samsung.com>