Incorporate Wall feedback that I received: two variables were uninitialized.
Always use "geant d = 0; RNDM(d)" instead of "geant d; RNDM(d)" - event though 'd' is not used for G4 builds, it triggers a warning.
Reenable Wall support for ICC builds with a proper set of suppressions derived from ICC 11.1.

We have to suppress two categories of warnings:
- 8 ROOT specific warnings (that we can't easily fix)
- 13 gbatch specific warnings (that we can tackle one after the other)

Rubber-stamped by V. Choutko.
Silence three more harmless warnings.
Merge branch 'master' into mkrafczy/TrdKModifications
Added changes to remove some warnings.