Open File... should work if no genome available

When a user wants to load data without loading a genome first, they can drag and drop a file (such as a .bed) into IGB. What happens behind the scenes is that IGB reads the file and tries to infer the structure of the genome from the file. This tends to work OK, depending on the file, and it is a useful feature.

However, if the user selects File > Open File... they receive a warning <Please select a Genome> and the data files does not get opened. Note: This behavior is the same if the Open File... button is clicked.

The default behavior should be: if a user drags and drops or selects Open File... before selecting a genome version, the data file should be opened within IGB, but a dialog should open with a message informing the user: "A genome sequence has not been selected, some features may be unavailable."

Task:
*Determine how to enable Load File... to open data when no genome is selected.
*Implement a solution.
*When data is loaded without a genome, warn the user "A genome sequence has not been selected, some features may be unavailable."