This quickly adds support for git URL with /tree/ inside in app installation.
It is intended to ease tests of apps which use new manifest format and helpers
for the 2.4 release. An example usage:
$ yunohost app install https://github.com/jeromelebleu/roundcube_ynh/tree/dev
As it will certainly change with the app category refactoring, it is not
documented and should be used with care.
The original app_id hard-coded replacement in scripts and hooks is replaced by
the use in app scripts directly of the given app_id argument (wip #126).
It's now the app maintainer responsability to make use of it in a way to
prevent colisions with other instances.
It passes the current app id to the app install/upgrade/remove scripts
as the last argument (wip #126).
The hook category has also been revisited to move some app specific parts
away from there. The action hook_check has been removed accordingly.
