$NetBSD$

Add DESTDIR support.

--- Makefile.orig	2014-12-18 21:10:00.000000000 +0000
+++ Makefile
@@ -158,7 +158,7 @@ size:
 	gzip < bpgdec | wc
 
 install: bpgenc bpgdec
-	install -s -m 755 $^ $(prefix)/bin
+	install -s -m 755 $^ $(DESTDIR)$(prefix)/bin
 
 CLEAN_DIRS=doc html libavcodec libavutil \
      jctvc jctvc/TLibEncoder jctvc/TLibVideoIO jctvc/TLibCommon jctvc/libmd5
