[gtkmm/gtkmm-3maybe] (35 commits) ...Fixed merge conflicts from master.

[Murray Cumming <murrayc src gnome org>]

Summary of changes:

  bc4b07c... ToolItem, ToolShell: Wrapped new C functions. (*)
  b3d21f3... Added some methods. (*)
  a46e65d... gdk/src/screen.hg: Added get_primary_monitor(). (*)
  b86160e... 2.19.7 (*)
  7c2b031... Demo: Fix use of deprecated API. (*)
  5747023... Comments changes. (*)
  0ed8da5... Regenerated C documentation XML files. (*)
  f465c23... Added a const version of get_drop_item(). (*)
  c44149e... Fix small API problems found by Jonathan Jongsma. (*)
  802acbc... 2.20.0 (*)
  235252f... Update MSVC project files (*)
  aa1dd05... Ifdef out inclusion of files no longer installed on Windows (*)
  397415f... Update installer files for 2.20 (*)
  453c087... TreeRowReference::get_model(): Correct the reference counti (*)
  b836400... RecentAction: Fix the constructor that takes a RecentManage (*)
  959ec22... Replace some @newin2p* with @newin{2,*}. (*)
  3cbbf3d... Really fix the @newin2p* in the *_override.xml files. (*)
  44858bf... API reference documentation: Remove gobjection-introspectio (*)
  def6a26... Builder: Complete the exceptions thrown documentation. (*)
  3e11890... 2.20.1 (*)
  dcfa636... 	Regenerate docs with the new docextract_to_xml.py script. (*)
  8dffcee... 	Regenerate docs once more to fix comment errors. (*)
  d3ec386... 	gdk_docs.xml: Another regeneration because of parsing erro (*)
  b9bd47c... 2.20.2 (*)
  97c1b78... Add main page to Doxygen documentation (*)
  5e7807c... [gtkmm.doap] Fixed invalid multiple objects on RDF properti (*)
  f1923c9... Improvements to main page documentation (*)
  89920e6... Minor main page changes. (*)
  95b44c1... Fix typo. (*)
  87853f4... Fix typo. (*)
  f0e425b... Link change in main page documentation (*)
  6b91d0f... FileChooser::get_filter(): Don't ref the result. (*)
  000a61c... 2.20.3 (*)
  edf8631... Mark the branch in the ChangeLog (*)
  92eb761... Fixed merge conflicts from master.

(*) This commit already existed in another branch; no separate mail sent