[devel] Cleanup of conditional compilation code and of background/gamma
handling. Internal changes only except for a new option to avoid compiling
in the png_build_grayscale_palette API (which is not used at all internally.)
The main change is to move the transform tests (READ_TRANSFORMS,
WRITE_TRANSFORMS) up one level to the caller of the APIs.
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index a276502..b240c34 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -43,6 +43,7 @@
#define PNG_ALIGN_MEMORY_SUPPORTED
#define PNG_BENIGN_ERRORS_SUPPORTED
#define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
#define PNG_CHECK_cHRM_SUPPORTED
#define PNG_cHRM_SUPPORTED
#define PNG_CONSOLE_IO_SUPPORTED