Patch from Robert Millan.

Add patches from libtool CVS.
* libtool.m4: Add kfreebsd*-gnu and knetbsd*-gnu.
* ltconfig: Likewise.
* ltcf-c.sh: Likewise.
* ltcf-cxx.sh: Likewise.
* ltcf-gcj.sh: Likewise.

From-SVN: r81213