Unified Buffer usage

[BenTokyo]

If not mistaken, the tool currently does not really use unified buffer (only GoogleNet / inception type of layer).
If 1 layer output can fit in the Unified buffer, and be used by the next layer, tool should actually configure DV to do so --> impact of performances and power consumption.

[ajkxyz]

Tool should also check available unified buffer size (--ub_size command line parameter) when generating source code.