Added band pixel access. (#56)
Added pixels.readBlock(), pixels.writeBlock(). (#56)
Also added support for reading into existing arrays.
Starting writing RasterBand tests.
Added obj creation/destruction logging.
Only remove objects from cache when they are destroyed (not in ObjCache.WeakCallback).
Fixed unsafe TOSTR() usage.
Merge branch 'gc-testing' into pixel-access
Added pixel access tests. (#56)
Also improved array length validation.