Instance-wide default VCS type
Currently, the default VCS type in the projects creation page is simply the first activated in the following ordered list: "Mercurial", "Git" and "Mercurial (native)". The activated ones are defined in the Admin Area.
We would need for the administrator to choose which one is to be the default instead.
Two use cases:
- some instances may be primarily geared towards Git, Mercurial being just a needed option for them.
- to make "Mercurial (native)" the default while allowing Git repositories (see for example foss.heptapod.net#95 (closed))