Remove single-config limitation from Eclipse WTP formatter

[nedtwigg]

• eclipseWtp('xml') in one subproject and eclipseWtp('css') in another will work fine, but...
• eclipseWtp('xml').configFile('a') in one subproject and eclipseWtp('xml').configFile('b') in another will not, and your build will fail with an exception that points you here

This limitation was introduced in TODO, in order to fix a bug in parallel builds. If you bumped into this problem, and it would help to fix it, please leave a comment to let us know that it is important to you. It is possible to fix it, but adds a fair bit of implementation complexity, which is why we will not implement it unless there is demand.

[nedtwigg]

The limitation never existed in the first place :D