TODO

* check for iconv
----------------
* debug 48kHz silence m2a files created by toolame (only one frame found)
+ release
+ regression tests
+ do not try to read directories
+ documentation
+ add missing messages to man page
! bitres handling in short frame
- detect encoder (lame tag, http://ff123.net/identify.html)
- option to output total play length (of all files)
- command line options to select checks to perform (begun)
- WAV haeder detection
- bitres gap: handle files that don't use bitres of more than 1 frame back
- crc: special handling of file crc 0x0000
- proper check for bitres use across tags (byte count instead of flag)
- warn when using skipped data in bitres?
- skipping 1 byte (not bytes)
- different format for header changes (at least if !OUT_HEAD1ST)
- id tag handling in own functions
- check for short ID3v1 in middle of file
- ID3v2 incremental parsing, compression support, ID3v2.2 unsync support
- split into multiple files (begun)
- compare fast-info calculations with frame-count calculations
- VBR: check frames and bytes against actual values, warn about tags in middle
- VBR: check toc against frame positions in stream
- VBR: handle header change to vbr better
- VBR: handle end of vbr not end of stream
- frame data length and crc for layer 2
- validity check on side info / main data
- check integrity of tags
- check devaition from bitstream rate
- compute length in MSF correctly if sample rate changes
- statistics
	min/av/max: bitrate, samprate, dlen, main_data_begin, bitres
	count: frames (good/bad), skiped bytes
	ms/i-stereo
F fix mp3