Implement Unicode TR-29 and TR-14

[rogerbinns]

This is needed to get #473 to work reasonably well, especially when one user perceived character is many unicode codepoints. The word splitting is also a lot better than trying to do it by codepoint category as in existing unicode61 (eg that messes up don't) and sentence splitting is good for a better snippet function.

• Generate break tables
• Test code from tables
• Grapheme cluster
• Word
• Sentence
• Unicode categories\
• Equivalent_Unified_Ideograph
• Emoji
• Regional Indicator
• Case folding
• Investigate tr14 line breaking for implementing textwrap
• textwrap
• Wide codepoints (east asian width == F or W)
• Grapheme cluster count
• Grapheme cluster range substring
• Grapheme cluster width
• Startswith / endswith
• find/index
• Set doc order to bysource and rearrange functions into logical doc order
• Grapheme cluster base char (remove diacritics equivalent)
• Compatibility codepoints (eg roman numeral ⅲ becomes latin iii)
• Update apsw.ext.format_query_table to use textwrap
• Update tests
• Convert important bits to C
• Convert other bits to C
• Rename module to unicode

[rogerbinns]

Equivalent_Unified_Ideograph should be investigated. Looks useful for stripped function for getting compatibility codepoint.