Problem: The column is not restored properly when the matchparen plugin is
used in Insert mode and the cursor is after the end of the line.
Solution: Set the curswant flag. (Christian Brabandt). Also fix
highlighting the match of the character before the cursor.
Problem: Matchparen only uses the topmost syntax item.
Solution: Go through the syntax stack to find items. (James McCoy)
Also use getcurpos() when possible.
Problem: Using a regexp pattern to highlight a specific position can be
slow.
Solution: Add matchaddpos() to highlight specific positions efficiently.
(Alexey Radkov)
Problem: On some systems case of file names is always ignored, on others
never.
Solution: Add the 'fileignorecase' option to control this at runtime.
Implies 'wildignorecase'.
Problem: Matchparen does not update match when using auto-indenting.
(Marc Aldorasi)
Solution: Add the TextChanged and TextChangedI autocommand events.
