Hardware buffer realloc

These patches introduce the reuse of allocated image memory buffers in the HwBuffer subsystem. The default behavior systematically releases the allocated buffers before satisfying a new request. The proposed patches try to keep the existing allocation to satisfy a new request. That is, if the buffer FrameDim does not change, only the difference between the current nb. of buffers and the requested one is applied.

Another change: buffers are released in the reverse order that they were allocated.

Code format was made more homogenous.

In addition to that, to commits introducing new macros in the Debug subsystem are proposed.