Copyedits and Practical Update

[Crissov]

Besides several copyedits, including clarifications and extended examples, this patch …

• adds TOTI Original Title frame
• adds TSOC Composer Sort Order frame
• adds several keywords for the TCON Content Type/Genre, TFLT File Type and TMED Media Type frames
• adds several predefined byte codes for the ETCO Event Timing Codes frame
• adds several predefined byte codes for the Picture type of the APIC Attached Picture frame
• renames TRSN and WORS by dropping Internet to just Radio Station Name and Official Radio Station Homepage, respectively
• splits out 4.2.5. Timestamp frames, 4.2.6. Sort order frames from 4.2.5. (now: 4.2.7.) Other text frames subsection
• updates Appendix A Genre List from ID3v1 with subsequent additions by Winamp etc.