Add defaults/shortcuts for frequently-used folders

[seansfkelley]

Unsure what this should look like. How does it interact with the Download Station-configured default location? Should it allow setting a new "default" locally to the extension? Setting the default in Download Station itself?

Correctness issues -- what if the folder no longer exists? We'd probably want to make a query for each shortcut to confirm it exists... every time the folder list is shown?

[brainchild0]

A favorites or recents list is probably more functionality than needed for a first iteration of such a feature, and is probably more suitable when interacting with complementary functionality on the back end rather than functioning entirely in the client.

Conventional client-only downloads in browsers follow a basic model, that downloads either begin immediately, in a default location, or after the user selects a target location from a prompt, which may originally show some location configured as the default, or the one used most recently. Download Station already supports a default location, which would be suitable in many cases, but some clients may need to be configured to override this service-side default with a per-client one.

I suggest the following enhancements:

1. Users may specify a default target directory for each instance of the session.
2. Downloads go into the per-instance default directory if given, otherwise the default directory given in File Station.
3. A second download action is added to the menu for downloading to location selected on-the-fly. The prompt should originally show the most location most recently chosen by the same method, if any, or otherwise, the location resolved in (2).
4. A recents list might be added later, but for performance and stability reasons, detection of missing locations should be limited to the time that such a target is manually chosen.

An alternative to (2), if supported by File Station, is moving the target of in-progress downloads, rather than selecting it before the download begins.