Fix several bugs

commit 49bcc402 (HEAD -> bug_fixes, thiblahute/bug_fixes2, thiblahute/bug_fixes, bug_fixes2) Author: Thibault Saunier tsaunier@igalia.com Date: Thu Mar 5 15:56:28 2020 -0300

ges: Make setting start/duration move or trim generic

We were implementing the logic for moving/trimming elements specific
to SourceClip but this was not correct ass the new timeline tree allows
us to handle that for all element types in a generic and nice way.

This make us need to have groups trimming properly implemented in the
timeline tree, leading to some fixes in the group tests.

This adds tests for the various cases known to not be handled properly
by the previous code.

Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/issues/92

commit 60b2e9ef Author: Thibault Saunier tsaunier@igalia.com Date: Wed Mar 4 17:42:46 2020 -0300

group: Update priority when a child is removed

Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/issues/93

commit c97bb2a7 Author: Thibault Saunier tsaunier@igalia.com Date: Wed Mar 4 17:16:18 2020 -0300

clip: Don't split clips at illegal position

Make sure that when we split a clip, the resulting timeline would
not be in an illegal state.

Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/issues/94