merge Search and Go to boxes+solution

Have one box in the header bar instead of the two: Search and Go to.

As the user starts typing, show a list of cards that begin with what they're typing. However, the top item on the list (which is selected) is "Search for <what they've typed>".

If the user hits return, do a search on what they've entered. If there is no exact match, offer to create a card of that name.

If they activate something else from the list (via clicking, or using the arrow keys to go up and down then hitting return), go to that card.

If they use the arrow keys to select something else from the list and hit the + key, put the item that was selected into the box, with a + after it, and list cards that begin with all that, again with the first item being "Search for <what they've typed>".

For bonus points, if they hit return with a card that exists in the box followed by a +, go to <card name>+*plus cards