The following patch addresses a bunch of issues: 
- Some incarnations of libtool (namely the one in Debian Lenny) need
  --tag even in this simple case
- We use the libtool .lo object extension, so we no longer interfere
  with the default rules for non shared objects
- Added missing -c for object generation
- Removed LTLINK var definition from compiler, this belongs only to the
  linker definition.
- Fixed the linker definition: there was CPP used, but linking is not
  done by the preprocessor...  :)