Item2665: Enhancements to ExplicitNumberingPlugin

Making several minor enhancements to this plugin.

• Clean up / remove global variables - not necessary.
• Make the "alphabet" a setting to permit alternative sequences of lettered headings.
• Allow alphabetic sequence to "wrap" if more numbered items than letters in the sequence. Previous version crashed with uninitialized string error.
• Disable plugin if not in View or Diff context.
• Changed regular expressions to be more tolerant of character locales. (using [[:upper:]] vs: [A-Z] )

-- GeorgeClark

Thanks for working on this plugin.

I will add some ideas on the ExplicitNumberingPlugin topic in Development web.

I have tried this plugin once and gave up on it because even if it appears to be brilliant it has a major usability problem.

-- KennethLavrsen - 20 Jan 2010