off by one error in lpf_peak_pick() filtering and filter coeffs brought into sync with Octave version

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1650 01035d8c-6547-0410-b346-abe4f91aad63
getting back into sync with C version of fdmdv, 21/23 tests passing

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1651 01035d8c-6547-0410-b346-abe4f91aad63
added test to confirm pilot coeff match to avoid getting caught by that again

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1652 01035d8c-6547-0410-b346-abe4f91aad63