Made makefile a little more portable, updated README

Makefile

@@ -3,9 +3,11 @@ override CFLAGS+=-Wall -Wpedantic -O2
 LDFLAGS=-lcrypto -lssl
 PREFIX=/usr/local
 MANPREFIX=${PREFIX}/man
+#Ubuntu uses the one below
+#MANPREFIX=${PREFIX}/share/man
 
 it:
-	${CC} ${CFLAGS} ${LDFLAGS} tubes.c -o tubes
+	${CC} tubes.c ${CFLAGS} ${LDFLAGS} -o tubes
 
 install: it
 	echo installing executable to ${DESTDIR}${PREFIX}/bin

README.md

@@ -10,6 +10,7 @@ tubes' defaults are configured within tubes.c by changing the values of the
 server and port variables at compile time. OpenSSL is a dependency of tubes;
 download the devel package from your distro.
 
-To install, cd into the cloned directory and `sudo make install`.
+To install, cd into the cloned directory and `sudo make install`. Some
+tweaking of the Makefile may be necessary, e.g. the location of local manpages.
 
 Custom compiler flags can be appended to the defaults, e.g. `CFLAGS=-fPIC`.