first pass at making an integer-only flavor of the libraries.  move FLAC__real out of ordinals.h to src/libFLAC/include/private/float.h, add FLAC__double and FLAC__float and use these everywhere instead of double and float, and don't typedef FLAC__real/float/double when building in integer-only mode.  still need to provide integer substitutes in several places.

make listbox for "from" charset contain only UTF-8 since that is the only support encoding for vorbis comments

remove the commented-out and erroneous end-of-stream setting in read_callback_(); fix another bug in seeking where landing after the last frame start would cause a seek error; improve the infinite-loop checker