Allow comic text to be optional. Patch from TobiX
Refactor: Move regualar expression scraping into a new class.

- This also makes "<base href>" handling an internal detail of the regular
  expression scraper, future scrapers might not need that or handle it in
  another way.
Convert starters and other helpers to new interface.

This allows those starters to work with future scrapers.
Fix some typos.
Move all regular expression operation into the new class.
- Move fetchUrls, fetchUrl and fetchText.
- Move base URL handling.
Change getPageContent to (optionally) return raw text.

This allows LXML to do its own "magic" encoding detection
Create new HTML parser based scraper class.
Add Blade Kitten as an example for the new parser.