rename variable in Transformer::translateFileConfig

Change-Id: I928eff9d1912146492c3801952e3bdd06adf412f
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
Do not put the plugins where the resources are.

That's not where they belong.
Also make less assumptions about the file path leading to them.
Ideally, we should also do the latter for the stuff in share/,
but then someone would have to touch the horrific qmake code in static.pro.

Task-number: QTCREATORBUG-10074
Change-Id: Ide9c4b83dcf0cd7a62b57643b79caf05662358cb
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>