Naming conflict on Mac OS

[matthiasrichter]

Mac OS is case insensitive which leads to a conflict for the Utilities/aliceHLTwrapper module definining the aliceHLTWrapper executable.
Reported in #359

• rename the devices of the module consistently (we anyhow started with a different naming scheme for devices)
• add a check on the cmake level in O2_GENERATE_EXECUTABLE

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