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>

 diff -durN ltrace-0.5.2.orig/Makefile.in ltrace-0.5.2/Makefile.in

 --- ltrace-0.5.2.orig/Makefile.in	2009-06-27 15:34:04.000000000 +0200

 +++ ltrace-0.5.2/Makefile.in	2009-06-27 15:34:27.000000000 +0200

 @@ -5,6 +5,7 @@

  OS		:= @HOST_OS@

  ARCH		:= $(shell echo "@HOST_ARCH@" |sed -e s/i.86/i386/      \

  						   -e s/sun4u/sparc64/  \

 +						   -e s/alpha.*/alpha/  \

  						   -e s/arm.*/arm/      \

  						   -e s/sa110/arm/      \

  						   -e s/ppc64/ppc/      \