Added a default Media element to silence light.exe.
candle.exe expects the Media element _not before_ the Package element. Also removed not needed attributes.
WiX doesn't use the parent directory's FileSource, but instead needs the full path for each file over and over again. To prevent cluttering the file, a variable (OpenVPNResources) was used to do this.
The Media element requires at least a cabinet name (8.3 filename only... is it still 1988?).
Increase InstallerVersion to 100 to prevent error LGHT0350 of light.exe.
Added some filetypes to .gitignore which are generated by the WiX toolset.