obnc: fix a few soft build failures from the ./install script

Compiling stuff in the do-install phase definitely isn't the proper
thing to do, but at least we're getting more stuff to build successfully.

obnc/Makefile

@@ -22,6 +22,7 @@ do-build:
 
 do-install:
 	cd ${WRKSRC} && \
+		${PKGSRC_SETENV} ${MAKE_ENV} \
 		./install \
 			--destdir=${DESTDIR}
 

obnc/PLIST

@@ -6,10 +6,35 @@ bin/obncdoc
 bin/obncdoc-extract
 bin/obncdoc-index
 bin/obncdoc-markup
+include/obnc/Files.h
+include/obnc/In.h
+include/obnc/Input0.h
+include/obnc/Math.h
 include/obnc/OBNC.h
 include/obnc/OBNCConfig.h
+include/obnc/Out.h
+include/obnc/Strings.h
+lib/obnc/Files.imp
+lib/obnc/Files.o
+lib/obnc/Files.sym
+lib/obnc/In.imp
+lib/obnc/In.o
+lib/obnc/In.sym
+lib/obnc/Input0.imp
+lib/obnc/Input0.o
+lib/obnc/Input0.sym
+lib/obnc/Math.env
+lib/obnc/Math.imp
+lib/obnc/Math.o
+lib/obnc/Math.sym
 lib/obnc/OBNC.env
 lib/obnc/OBNC.o
+lib/obnc/Out.imp
+lib/obnc/Out.o
+lib/obnc/Out.sym
+lib/obnc/Strings.imp
+lib/obnc/Strings.o
+lib/obnc/Strings.sym
 man/man1/obnc-compile.1
 man/man1/obnc-path.1
 man/man1/obnc.1

obnc/TODO

@@ -1,12 +1,9 @@
-- ./install tries to build extra stuff, and is rigged to ignore those
+- ./install tries to build extra stuff, and is rigged to ignore any
   errors and keep going, as those components are considered optional.
 
   We might want to consider patching that out and cause a hard-failure
-  if errors are detected, since things randomly not getting built/installed
-  might not play nice with PLIST.
-
-- PLIST currently doesn't include everything, due to the soft build failures
-  noted above. It may also be responsible for obnc-libstd failing to build too.
+  if errors are detected, and/or move building them into ./install, as things
+  randomly not getting built/installed might not play nice with PLIST.
 
 - Something built by ./install wants libSDL, so we'll want to use the Options
   framework to selectively-enable using it (which'll probably require patching