Adding sysroot support (without a specified sysroot), for those who need --sysroot in their x-toolchains.
Using the full cross-prefix as the sysroot to avoid / pollution.
Update binutils-2.23.2 patch for newer Texinfo

With some newer versions of Texinfo (>=5), binutils has invalid commands
within its documentation.  Correct this in order to avoid errors like:

config.status: creating po/Makefile
../../../bfd/doc/bfd.texinfo:325: unknown command `colophon'
../../../bfd/doc/bfd.texinfo:336: unknown command `cygnus'
make[3]: *** [bfd.info] Error 1

--HG--
extra : rebase_source : 593c596c7f68df45b6ddabeb169e8d9c86d59e57
build.sh: do not fail without makeinfo installed on the host

fixes #8