Use LIBS instead of LDFLAGS to ensure correct order of linker arguments and move linux-specific defs into linux section, add librt on linux as well.
Use LIBS instead of LDFLAGS to ensure correct order of linker arguments
and move linux-specific defs into linux section, add librt on linux
as well.

jevonearth/rtpproxy,hongbinz/rtpproxy,dsanders11/rtpproxy,hongbinz/rtpproxy,hongbinz/rtpproxy,jevonearth/rtpproxy,synety-jdebp/rtpproxy,synety-jdebp/rtpproxy,Vocalocity/rtpproxy-pre,Vocalocity/rtpproxy-pre,dsanders11/rtpproxy,sippy/rtpproxy,Vocalocity/rtpproxy-pre,jevonearth/rtpproxy,dsanders11/rtpproxy,hongbinz/rtpproxy,sippy/rtpproxy,Vocalocity/rtpproxy-pre,jevonearth/rtpproxy,synety-jdebp/rtpproxy,sippy/rtpproxy,synety-jdebp/rtpproxy