Add Case-Insensitive Mode

[SicroAtGit]

Discussed in #27

New Syntax:

• (?i) means that everything after that is case-insensitive.
• (?-i) means that everything after that is case-sensitive.

New Parameter

• AddNfa(..., regExModes = 0)
  • AddNfa(..., "a", #RegExMode_NoCase) is the same as AddNfa(..., "(?i)a")

Groups inherit the active modes of the context outside. Mode changes within a group has no effect on the context outside this group.

The implementation will use Unicode's Simple Case Folding variant (single character code point to single character code point), but in reverse: Instead of mapping all character variations to a single character (folding), a single character is mapped to all character variations (unfolding). This is necessary because the DFA must know all valid characters.

The source file from which the translation table will be created:
https://www.unicode.org/Public/UCD/latest/ucd/CaseFolding.txt