Initial attempt at making a progress bar

The search operation can take a while to complete and was locking JOSM up
during this time. It is better practice to at least throw up a progress bar.

Currently the progress bar is displayed but then doesn't get closed when the
search is done.
Fixing the never vanishing progress dialog
Improving error handling and progress monitoring in search method
Removing unused import
Moving note download into a runnable

This will let it play nicer with other background runnable tasks
Adding a progress dialog when processing offline queue
Adding a call to the translate function for a user facing string
Merge pull request #27 from iandees/search-progress-bar

Adding progress bars for long operations