add --disable-xmms-plugin option to prevent building the xmms plugin (sf#930494 https://sourceforge.net/tracker/index.php?func=detail&aid=930494&group_id=13478&atid=363478)

add configure options --disable-thorough-tests which breaks up testing into 3 levels: 0 for basic testing, 1 for thorough testing, 2 for exhaustive testing

use flac file name instead of dummy.wav for --export-cuesheet-to (sf request #1272825 https://sourceforge.net/tracker/index.php?func=detail&aid=1272825&group_id=13478&atid=363478)

add --disable-doxygen-docs options (sf patch #1365935 https://sourceforge.net/tracker/index.php?func=detail&aid=1365935&group_id=13478&atid=313478)

fix calculation bugs in encode_subframe_(): max_qlp_coeff_precision when qlp_coeff_prec_search; account for qlp coeff overhead in guessing the best lpc order; default to hann instead of rectangular window on assertion failure

fix bug in return value for FLAC__stream_decoder_set_metadata_respond_application() and FLAC__stream_decoder_set_metadata_ignore_application() (sf #1235005: https://sourceforge.net/tracker/index.php?func=detail&aid=1235005&group_id=13478&atid=113478)

fix bug: -a and -t were not prevented from being used together (sf #1229481: https://sourceforge.net/tracker/index.php?func=detail&aid=1229481&group_id=13478&atid=113478)