Remove some confusing syntax pointed out by ghudson.
Remove some confusing syntax pointed out by ghudson.

* build/ac-macros/swig.m4
  test doesn't need square brackets around it.
  Prefer -o over two test invocations with ||

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion