Stop automake complaining that it will change its behaviour in future releases


git-svn-id: https://svn.modelica.org/projects/Modelica/branches/maintenance/3.2.1@7125 7ce873d0-865f-4ce7-a662-4bb36ea78beb
- Look for OSX when deciding if we have access to POSIX functions
- More checks for realpath() (OSX did not set any in the list)


git-svn-id: https://svn.modelica.org/projects/Modelica/branches/maintenance/3.2.1@7148 7ce873d0-865f-4ce7-a662-4bb36ea78beb