0.25.0

• Changed in NumericPlugValueWidget the methods __keypress and __textChanged to be protected
• Added alternate color as new entry in widget style sheet
• The GafferUI.Image class now uses a more sensible cache size to eliminate thrashing when loading images from disk. The cache size defaults to 100 MB but can be specified directly using the GAFFERUI_IMAGECACHE_MEMORY environment variable, which is also interpreted as being a number in MB.