Update INSTALL

INSTALL

@@ -18,4 +18,37 @@ this package.
 
    The `configure` shell script attempts to guess correct values for
 various system-dependent variables used during compilation. It uses
-those values within a `Makefile` in
+those values within a `Makefile` to build for that POSIX system as
+defined by `config.mak` which was generated by `configure`.
+
+Compilers and Options
+=====================
+
+  Some systems require unusal options for compilation or linking that
+the `configure` script does not know about. If you run into an issue
+run `./configure --help` to figure out what you can do to fix the
+behavoir.
+
+Installation Names
+==================
+
+  By default, `make install` installs the package's command under
+`/usr/local/bin`. You can specify an installation prefix other than `/usr/local/`
+by giving `configure` the option `--prefix=PREFIX` to `configure`, the package uses
+PREFIX as the prefix for installation programs and libraries.
+Documentation and other data files still use the regular prefix.
+
+`configure` Invokation
+======================
+
+  `configure` recongizes the following options to control its operations.
+
+  `--help`
+     Prints a summary of all the options to `configure`, and exits.
+  `--prefix=PREFIX`
+     Sets the installation prefix.
+  `CFLAGS`
+    Sets the flags used during compilation.
+
+`configure` also accepts some other options. Run `configure --help` for more
+details