Update item for install with spaces:

>   There are two capabilities here, first the ability to build from a
>   source directory that contains spaces, and second the ability to install
>   into a directory that contains spaces.  The first is probably not
>   possible because 'gmake' and other compiler tools do not fully support
>   spaces in path names.  The second is possible with proper quoting in
>   the makefiles.  Because PostgreSQL supports relocatable installs, it
>   is possible to install into a directory that doesn't contain spaces and
>   then copy the install to a directory with spaces.