use `apr-config --link-libtool --libs`

[Peter Johansson]

related to ticket:319

help output from apr-config v0.9.17 says

hen linking with libtool, an application should do something like:
  APR_LIBS="`apr-config --link-libtool --libs`"
or when linking directly:
  APR_LIBS="`apr-config --link-ld --libs`"

and as we are indeed using libtool so we should use the option --link-libtool. However, changing straight ahead makes the following svn test to fail.

Also, we should add the --libs option (although these libs might not be needed for the functionality we are using (at least not yet))

[Peter Johansson]

The --libs option is not needed. Only libs used directly need to be added to LIBS, because libtool takes care of adding secondary libs. Magic!

[Peter Johansson]

(In [679]) closes #320 - we are no longer using libtool and therefore no reason to use apr-config option --link-libtool. OTOH since we are not using libtool I added a a line to catch libs needed for apr.