Fixed variable name in javadoc
Create empty image using correct number of bands . GEOT-4633 - Reload configuration
Fixed OutOfMemoryErrors on image rescaling when zooming out  (GEOT-4045). Fixed result image imprecision on large zoom in (up to 25-50 times):
- Instead of generating a start image, applying db tile image onto it and then rescaling - now rescaling images as soon as we get them from db.
- Instead of applying db tile images on the top of start image - now using JAI image mosaic as it offers better precision at positioning image parts (can specify float values instead of integers)
- Using floats where possible to increase precision