Get rid of isinf redefinition warnings for qt_example build by defining PL_HAVE_ISINF and PL__HAVE_ISINF for the case when config.h is not available.
Get rid of isinf redefinition warnings for qt_example build by defining
PL_HAVE_ISINF and PL__HAVE_ISINF for the case when config.h is not available.

svn path=/trunk/; revision=10252

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