Feature/lsb frontpage

Made seperate theme for lesersokerbok.no, since there are some custom poste types etc. coming up that should not be in the base theme.

New theme has frontpage template similar to boksok.no. Two types of sections are ready, and that is enough to push to lsbtest for testing on librarians etc.

Also consists of some base theme clean up.
Denne burde kanskje hete noe annet, siden det ikke er en book section, men noe mer generisk? Eller det bare for tjenester? 'register_field_group_service_section_field_group'