Restore install target

INSTALL

@@ -1,8 +1,7 @@
 INSTALLATION INSTRUCTIONS
 
-To build and install the libfec libraries, simply say
+To build and install the libfec libraries for the host platform, say
 
-./configure
 make
 make test (optional)
 make install (as root)
@@ -11,6 +10,19 @@ By default, "make install" puts the libfec libraries in
 /usr/local/lib, the include files in /usr/local/include, and the
 manual page in /usr/local/man.
 
+To build a specific platform target, use one of:
+
+make linux
+make macos
+make windows
+
+Use DESTDIR for staged packaging installs, for example:
+
+make install DESTDIR=/tmp/libfec-package
+
+You can override prefix, libdir, includedir and mandir on the make
+command line.
+
 You may have an old version of the GNU assembler that cannot handle
 the relatively new SSE2 mnemonics. Update your version of the GNU
 "binutils" package.
@@ -22,8 +34,7 @@ http://sources.redhat.com/binutils/
 
 TESTING THE FEC LIBRARY
 
-After running the ./configure script, optional tests can be built and
-run as follows:
+Optional native tests can be built and run as follows:
 
 make test
 
@@ -36,4 +47,3 @@ broken.
 Phil Karn, karn@ka9q.net
 
 
-