Add some bitmap tests that test some corner cases of PNG loading.

Author: SiegeLordEx

examples/data/gradient_gamma.png

@@ -0,0 +1,21 @@
+# Test various edge cases with color spaces etc.
+
+[bitmaps]
+mysha256x256_16bit=../examples/data/mysha256x256_16bit.png
+gradient_gamma=../examples/data/gradient_gamma.png
+gradient_linear=../examples/data/gradient_linear.png
+
+[test gradient linear]
+op0=al_clear_to_color(red)
+op1=al_draw_bitmap(gradient_linear, 0, 0, 0)
+hash=ac15184e
+
+[test gradient gamma]
+op0=al_clear_to_color(red)
+op1=al_draw_bitmap(gradient_gamma, 0, 0, 0)
+hash=9005cf00
+
+[test 16bit]
+op0=al_clear_to_color(red)
+op1=al_draw_bitmap(mysha256x256_16bit, 0, 0, 0)
+hash=70059efa