implemented basic error system; restructured some files; replaced a few asserts

src/rwerror.h

@@ -0,0 +1,25 @@
+namespace rw {
+
+struct Error
+{
+	uint32 plugin;
+	uint32 code;
+};
+
+void setError(Error *e);
+Error *getError(Error *e);
+
+#define _ERRORCODE(code, ...) code
+char *dbgsprint(int32 code, ...);
+
+/* ecode is supposed to be in format "(errorcode, printf-arguments..)" */
+#define RWERROR(ecode) do{          \
+	rw::Error _e;                   \
+	_e.plugin = PLUGIN_ID;      \
+	_e.code = _ERRORCODE ecode; \
+	fprintf(stderr, "%s:%d: ", __FILE__, __LINE__); \
+	fprintf(stderr, "%s\n", rw::dbgsprint ecode);       \
+	rw::setError(&_e);              \
+}while(0);
+
+}