Log Message:
Update adwaita-icon-theme to 3.20

3.20
  - win32 build fixes

3.19.91
  - application-x-addon-symbolic
  - win32 build fixes
  - win32 grey shadows fixed (bug #763034)

3.19.90
  - lighter fullcolor folders
  - thicker stroke for non-starred-symbolic
  - emblem-new metaphor sync
  - call-start call-stop symbolic shape improvements
  - mark-location-symbolic improved shape
  - edit-cut shape improvement
  - simplify hdd symbolic shapes
  - document-edit-symblic
  - visual separation between list and grid view and hamburger menu
    (symbolic)
  - symbolic wifi-acquiring bugfix
  - specfic icon grid for gnome-shell
  - windows build system scripts

3.18.0
  - improved view-list-symbolic
  - cursors working on KDE
  - translations

3.17.4
  - updated folder-new-symbolic

3.17.3
  - updated cursors, support for win32
  - address-book-new fix
  - ebook device icon
  - updated select-all metaphor
  - removed widget assets form an icon theme
  - privacy-mode symbolic icon
  - intltool fixes
  - translations