ATLAS LCG Configuration For CMake

This package collects all the code for including LCG packages into the build of ATLAS projects.

Projects needing an LCG release should set it up like:

set( LCG_DIR ${CMAKE_SOURCE_DIR}.../AtlasLCG )
set( LCG_VERSION_POSTFIX "" )
find_package( LCG 87 REQUIRED )

The LCG_VERSION_POSTFIX variable can be used to pick up LCG releases like LCG_81b and similar.

Once the LCG release was found, the project is expected to find the individual LCG components using specific find_package(...) calls for those packages. The modules subdirectory holds the "find modules" for all of the externals that are supported for pickup from an LCG release.