In this folder Ado keeps its configuration files.
Here we have also the database files which are distributed 
with Ado by default.
These files are supposed to change locally but local 
changes usualy do not have to go upstream.

To ignore such files but keep them versioned
one have to run the command "git update-index".
Here is an example with ado.conf.
  git update-index --assume-unchanged etc/ado.conf

To make git track the file again, when you have a change 
that you want to push upstream, simply run:
  git update-index --no-assume-unchanged path/to/file.txt.

See also:
https://help.github.com/articles/ignoring-files#ignoring-versioned-files