Branch libreoffice-7-3

Branch libreoffice-7-3

This is 'libreoffice-7-3' - the stable branch for the 7.3.x releases.
The commit rules are different according to the development phase:

A. 7.3.0 beta phase:

   A. any bug fixes are allowed without review
   B. late features need approval by 3 people with different affiliation

B. 7.3.0 rc phase and later:

   A. fixes need approval by one reviewer
   B. late features need approval by 3 more people with different affiliation

IMPORTANT: Every developer is responsible for pushing the fixes into all
          appropriate branches. Note that we do not plan any merge
          from this branch to master or vice versa.

Please, help use to make stable and usable release. If you want to build
something cool, unstable, and risky, use master.