Changes to assist in building on Linux, more attempts at stopping OpenJPEG(?) related crashes, disabled being logged out for going AFK by default.

indra/llimagej2coj/llimagej2coj.cpp

@@ -114,6 +114,7 @@ BOOL LLImageJ2COJ::decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decod
 	// FIXME: Get the comment field out of the texture
 	//
 	if (!base.getData()) return FALSE;
+	if (!base.getDataSize()) return FALSE;
 
 	LLTimer decode_timer;
 
@@ -419,6 +420,7 @@ BOOL LLImageJ2COJ::getMetadata(LLImageJ2C &base)
 	// FIXME: We get metadata by decoding the ENTIRE image.
 	//
 	if (!base.getData()) return FALSE;
+	if (!base.getDataSize()) return FALSE;
 
 	// Update the raw discard level
 	base.updateRawDiscardLevel();