Various bugfixes
louis:translate-file: add @pages attribute with page count
Make parsing-helper.xsl more powerful

* possible to have multiple rulesets in the inline stylesheet (e.g. {...} @page {...} ::before {...})
* put regex helper functions in separate file
* did some renaming too
louis:translate-file: prefix page-layout options with louis:
Move validate-braille to utilities and use in louis:format
braillecss: support counter-reset
louis:translate-file: add 'louis:braille-page-begin' parameter
Include @page {...}, ::before {...} and ::after {...} in CSS @style attribute

* css:inline replaces css:apply-stylesheet
  - doesn't have a page-layout output port anymore
  - doesn't insert css:before and css:after elements anymore
  - puts everything in the @style attribute instead
* block-translator-template becomes responsible for translating ::before and ::after pseudo-elements
* louis:format now has to do more CSS parsing
  - extract page-layout info from inline CSS
  - extract ::before and ::after content
louis:format: page numbering improvements

- support counter-reset: braille-page ...
- make sure page numbering is still correct when document is split in multiple sections
fixup 9787a2ed7366069d
louis:format: proper whitespace handling