#25: Attached site to theme
#25: Use theme configured for site
#25: Clear site cache if theme is updated
#25: Duplicate virtual host exception not thrown if host is empty
#25: More generic main template. Variable head section
#25: Higher code views
#25: Deleted CSS field
#25: Clear page cache if page layout is updated
Merge branch 'feature/#25-assign-theme-to-site' into develop