ieboilstart: add setting to install adofiles locally

[bbdaniels]

One common issue with projects is that they rely on installed versions of commands from SSC and therefore authors fail to install user-written commands, causing repeated crashes in replication.

ieboilstart could resolve this by setting the adopath for the current session to an /ado/ folder inside the project directory. In Stata this would be done by something like:

sysdir set PLUS `"${DataWork}/ado/"'

This sets the location of the ado folder for the duration of the Stata session and it is reset to default on restart. This could be passed as a using option in ieboilstart for example but it would unfortunately not usually allow globals to used (since ieboilstart clears globals IIRC).

[kbjarkefur]

This is an interesting idea. Let me explore this a little when I find time.

The only issue that I see with this is that it will make us pus other peoples ado files to our repos on GitHub. And it is not obvious that we have the right to do so. Not super critical, but we should do some thinking regarding that.