Lift single service program directory restriction

[SanjulaGanepola]

Fixes #158

[kaspervanderhulst]

Is there any idea when this one will be merged and live? :)

[arco400]

@SanjulaGanepola @edmundreinhardt any idea if and when this change will be merged?

[richardm90]

@SanjulaGanepola, I've just tried using Source Orbit for the first time, to transfer source from source files to a local directory (using the Project Explorer > Migrate Source option) and immediately ran into the #158 issue and then stumbled on this PR. I have rerun the source migration using the fix in this PR and it worked or at least it completed. I'm not exactly sure what the tooling is supposed to do in respect to service programs but I did have to manually tweak the TOBI build files afterwards. The source I migrated was for a very simple application that had two service programs and it tried to create a single service program. But at least this fix allowed the tooling to run to completion. The migrated source was not perfect, the tooling did some really weird stuff with my copybooks, but I'll investigate separately and raise issues accordingly.