FVS: Make the location of the FVSOut.db a configurable parameter

[lbross]

This is an enhancement request. Currently BioSum requires the FVSOut.db file to be at the root of the /fvs/data folder. Sometimes we need to load data from multiple FVSOut.db files into a project. Add a button and interface to be able to browse to the FVSOut.db. By default it should continue to point to /fvs/data.