make codec_resample build on __CYGWIN__, and make it load on FreeBSD

(and probably other systems as well).
Both need libresample.a to be specified in the linking phase,
and cygwin needs <float.h> as other BSD.

The checks for OS-specific headers should really be moved to some
common header though.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@95625 65c4cc65-6c06-0410-ace0-fbb531ad65f3