config dir should be hidden (on Unix)

[anatol]

Currently vmd uses File::HomeDir + 'vmd-0.05' and on Unix it is a folder in Home that pollutes filesystem.

vmd config dir should be hidden, either

~/.vmd or ~/.config/vmd

for the latter one you might want to use "File::ConfigDir->xdg_config_home;" instead of "File::HomeDir->my_data;"