replace libtool* with glibtool* on Darvin
Darvin seems to have a libtool from NeXT that conflicts with the one from GNU.
Based patch daa8fd5bda603f109934e06abf6d42a053be5e49 (https://github.com/leobelen/dia/commit/daa8fd5bda603f109934e06abf6d42a053be5e49) from Leonardo Javier Belen leobelen@gmail.com.