Allow multi-word "install" command.

Autoconf can determine that the correct install command includes flags,
e.g., "/usr/bin/install -c". When using this as a command, we can't
enclose the value in double-quotes, as that makes some shells use the
whole expression as a filename:

# this is the value returned by autoconf and stored in CT_install
$ ins="/usr/bin/install -c"

# if we call it with quotes, the command is not found
$ "${ins}"
bash: /usr/bin/install -c: No such file or directory

# removing the quotes lets it work as expected
$ ${ins}
/usr/bin/install: missing file operand
Try `/usr/bin/install --help' for more information.

Signed-Off-By: Anthony Foiani <anthony.foiani@gmail.com>

     1.1 --- a/scripts/populate.in	Mon Apr 09 11:00:35 2012 +0200
     1.2 +++ b/scripts/populate.in	Thu Apr 26 19:55:59 2012 -0600
     1.3 @@ -205,7 +205,7 @@
     1.4                  *)      mode=0644;;
     1.5              esac
     1.6              ${CT_PRINTF} "      installing as '%s/%s', mode='%s'\n" "${dir}" "${true_libname}" "${mode}"
     1.7 -            "${install}" -m "${mode}" "${libfile}" "${dir}/${true_libname}"
     1.8 +            ${install} -m "${mode}" "${libfile}" "${dir}/${true_libname}"
     1.9              do_resolve_deps "${dir}/${true_libname}"
    1.10              return 0
    1.11          fi