rpng v1.5

New version features:

• ADDED: Support indexed data loading and saving (PLTE, tRNS)
• ADDED: rpng_load_image_indexed() (+ memory version)
• ADDED: rpng_save_image_indexed() (+ memory version)
• ADDED: Automatic join of IDAT chunks when loaded
• REVIEWED: Crashes on images loading not found

Enjoy rpng!