Make tk86.pc work with the installed tcl86.pc.

Mimic the port and require the exact Tcl version.

x11/tk/8.6/Makefile

@@ -1,10 +1,11 @@
-# $OpenBSD: Makefile,v 1.15 2017/11/04 18:55:51 stu Exp $
+# $OpenBSD: Makefile,v 1.16 2017/11/22 12:46:04 stu Exp $
 
 COMMENT =		graphical toolkit for Tcl
 
 P =			7
 DISTNAME =		tk8.6.${P}
 PKGNAME =		tk-8.6.${P}
+REVISION =		0
 SHARED_LIBS =		tk86 1.${P}
 CATEGORIES =		x11 x11/tk
 HOMEPAGE =		http://www.tcl.tk/

x11/tk/8.6/patches/patch-unix_tk_pc_in

@@ -0,0 +1,17 @@
+$OpenBSD: patch-unix_tk_pc_in,v 1.1 2017/11/22 12:46:04 stu Exp $
+
+Make tk86.pc work with the installed tcl86.pc.
+Mimic the port and require the exact Tcl version.
+
+Index: unix/tk.pc.in
+--- unix/tk.pc.in.orig
++++ unix/tk.pc.in
+@@ -9,7 +9,7 @@ Name: The Tk Toolkit
+ Description: Tk is a cross-platform graphical user interface toolkit, the standard GUI not only for Tcl, but for many other dynamic languages as well.
+ URL: http://www.tcl.tk/
+ Version: @TK_VERSION@@TK_PATCH_LEVEL@
+-Requires: tcl >= 8.6
++Requires: tcl86 = @TK_VERSION@@TK_PATCH_LEVEL@
+ Libs: -L${libdir} @TK_LIB_FLAG@ @TK_STUB_LIB_FLAG@
+ Libs.private: @XFT_LIBS@ @XLIBSW@
+ Cflags: -I${includedir}