Initial commit

Part of the code copied from
https://wiki.archlinux.org/index.php/Dropbox#Multiple_Dropbox_Instances
Separate config from executable

Configuration is stored as specified in the XDG specification.
Users will add paths separated by a new line for each dropbox instances
that they want to make.
Fix bug that prevents dropbox from running gui

Since each of the instances are of a separate "home", the configuration will
differ from user. One case is running X. Each instances are blocked to be run
as a gui because they don't have .Xauthority which X uses for authenticating
local client. A symlink will do.
Fix whitespace issues
Supress std{out,err} and run in the background

Dropbox program does not fork so it needs to be run the background
so that other dropboxes will also be run.
Link .gtkrc-2.0 from home

This will maintain the consistency with the user chosen theme. Because
the dropboxes reside on different folder that they believe is $HOME, settings
will be not the same as the user.
Add README file
Create parent directory if it does not exist