Install libocsync to lib/ without subfolder.

Install libocsync to lib/ without subfolder.

Installing to lib/${APPLICATION_EXECUTABLE} has caused a bunch of
irritations in the past and subtle annoying to fix bugs. To avoid name
clashes with branded clients ${APPLICATION_EXECUTABLE} becomes now
part of the filename instead of the subfolder.

The concrete motivation to change this now is that on Windows there
is no RPATH and it's not possible to run owncloud directly from the
Craft Root folder, which is nice when you're developing on Windows.

It would have been possible to change this just for Windows but as
written earlier this has caused lots of issues and thus I think it's
a good idea to just stay consistent accross platforms when touching it.