Autoscroll file tree presenter when opened

[hernanmd]

Currently opening File Browser presenters does not auto-scroll the "Directories" presenter to the current working directory.

Actually, the directory which is shown in the file system navigation presenter is not in sync with the expanded tree (expansion of the tree to the current directory was working some weeks ago, probably got lost in a commit).

Related to this task is the integration of a working method to scroll to a selection in Spec.