'Move file up/down' keybindings should be scoped to solution explorer

[latkin]

We have an internal bug tracking this, wanted to make it public.

Our current keybindings for the "move file up", "move file down" actions are globally-scoped. This means we hijack Alt-Up, Alt-Down in some places where we don't need to.

In particular, the Find and Replace dialog also uses these keys, and is getting broken by us.

Fix should be simple - scope our keybindings to Solution Explorer only.

[ricksladkey]

This is great! Thanks a lot.