Added option "startCodepoint" to define start code point value

[ramirezcgn]

No description provided.

[danyball]

I also need this feature. Is there anybody who can review this PR?

[danyball]

Maybe someone can also use this workaround:

Handlebars.registerHelper("subtract4352", function (value) {
  // we want a codepoint start at hex E001 - decimal 57345 --> subtract 4352
  return value - 4352
})

Usage:
{{ codepoint (subtract4352 this) }}