WIN32: fix roken build

__declspec not _declspec

Include "err.h" not <err.h>

Include "roken.h" before "err.h"

Indent "#if" as "# if" within roken.h.in when CPP rules must be copied
into the generated "roken.h".

Correct verr() attribute to be ROKEN_LIB_NORETURN_FUNCTION.

Change-Id: I4289ecaba4a097175b4a5a1cde529b59038c72e3

lib/roken/verr.c

@@ -36,7 +36,7 @@
 #include "roken.h"
 #include <err.h>
 
-ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
+ROKEN_LIB_NORETURN_FUNCTION void ROKEN_LIB_CALL
 verr(int eval, const char *fmt, va_list ap)
 {
     rk_warnerr(1, fmt, ap);