eqlms: cleaning up API description in source
build: adding configure preference order for C compiler
Merge branch 'master' of ssh://50.116.63.58/home/jgaeddert/git/liquid-dsp
build: fixing build to check for specific gcc compiler flag

  * adding m4 macro from autoconf-archive repository
  * checks for specific gcc -march or -mtune flag
  * currently still need AX_EXT macro to check for intrinsics headers
  * still need to fix compiler bug in OS 10.9 using llvm in configure.sh
build: changing support address to <support@liquidsdr.org>
build: removing auto-generated aclocal.m4 macro in 'distclean' target
build: removing duplicate AC_PROG_CC check
math/poly: making function prototypes for findroots global
framing/detector: fixing memset() call to avoid compiler warnings