Define an interface libarary for exported headers.

Define an interface libarary for exported headers.

Now with LCG_97a (ROOT 6.20/06) these workarounds/hacks were
actually causing problems for the jobs. Without them the jobs
can run successfully though.

There is already a library that provides the public headers and hence
the `atlas_install_headers` is redundant.

Library dependency fixes.

Fix or remove `atlas_install_*` statements that do not reference any
files.

Avoid spurious object copy in range for.

Library dependency fixes.

Library dependency fixes.

Library dependency fixes.

Currently the InDetTrigExtensProcessor relies on the scoring tool to
create the track summary and store it in the track, which violates
const-ness.

- Ensure that TRT shared hit counting starts at zero.
- Only increase TRT shared hit counter if it is a TRT hit.

Inconsistent indentation.

Avoid spurious object copy in range for.

Remove one of the TRT_DriftCircleOnTrack,if not used we can do eager inititialization of m_globalPosition