gnucash maint: Tweak appdata file generation some more

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash/commit/dd181289 (commit)
	from  https://github.com/Gnucash/gnucash/commit/7a16e048 (commit)



commit dd1812892747e37bacff1bb428c8bda4a98fc2c2
Author: Geert Janssens <geert at kobaltwit.be>
Date:   Mon Feb 17 14:13:18 2020 +0100

    Tweak appdata file generation some more
    
    Should make it easier for packagers to provide their own releases data.



Summary of changes:
 CMakeLists.txt                                     |  8 +++++-
 cmake/CMakeLists.txt                               |  4 +--
 cmake/configure-appdata.cmake                      | 33 ++++++++++++++++++++++
 ...-data.cmake => configure-gnucash-desktop.cmake} |  8 +++---
 gnucash/gnome/CMakeLists.txt                       | 10 +++----
 gnucash/gnome/gnucash.appdata.xml.in.in            |  2 +-
 gnucash/gnome/gnucash.releases.xml                 |  1 +
 7 files changed, 53 insertions(+), 13 deletions(-)
 create mode 100644 cmake/configure-appdata.cmake
 rename cmake/{insert-vcs-data.cmake => configure-gnucash-desktop.cmake} (75%)
 create mode 100644 gnucash/gnome/gnucash.releases.xml