Managed uniform buffer support.

Managed uniform buffer support.
Single uniform buffer is created in order to store uniform data for all rendered items.

- UniformBuffer is made of one or many Graphics::Buffer objects
- Memory of UniformBuffer is continuous
- UniformBuffer may resize if needed
- UniformBufferView is now used to access uniform data for individual items
- UniformBUfferPoolView manages memory allocation using stack/pool allocation strategy
- UniformBufferPoolView lives only through a single frame and then rolls back all memory

Change-Id: I2f1d2a007a132a7745b6927912353f57a96be791