fix bug in changing `css` to `scss`
skeleton of header picture change plugin #110
handy file upload plogin #110
header upload #110

- file saved onto filesystem
- metadata saved into database
- input file displayed in admin interface
`header.php` polished a little #110
header image used in header #110
display header with filter `dzogchen_custom_header` #110

Seems to work in situations
- filter is not there
- filter doesn't find a new picture
- filter finds the picture in the db
Merge remote-tracking branch 'origin/master' into i110

Conflicts:
	wp-content/themes/dzogchen/src/style.scss
	wp-content/themes/dzogchen/style.css
add display of custom header deletion checkbox #110
enable deletion of the custom image #110
adding link from header picture - admin gui #110
display link at page #110

- display link if specified on every page
- allow changing link and upload image seperataly, they don't need to be
  provided both together
prefil link input with value already stored in db #110
Merge pull request #127 from coubeatczech/i110

I110