lib/string_exp/utf8: Introducing UTF-8 basics for String.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Adapted the construction from a CString to work with UTF-8.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Adapted * for FlatString with UTF-8 chars

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Added routine to compute code point on a UTF-8 character.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: UnicodeChars can be tested for strict equivalence.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Adapted reverse service on UTF-8 strings.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Substring now works with UTF-8 strings (pre-indexed).

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Implemented to_upper/to_lower on UnicodeChar.
lib/string_exp/utf8: to_upper/lower usable with UTF-8 strings.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/string_exp/utf8: Output usable with UTF-8.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>