- change system/controlDict to use functions {..} instead of functions (..);
* This is internally more efficient
- fixed formatting of system/controlDict functions entry
- pedantic change: use 'return 0' instead of 'return(0)' in the applications,
since return is a C/C++ keyword, not a function.
- if mandatory is true, findEtcFile() will abort with a message (via cerr).
This allows a non-existent file to be caught at the lowest level and avoid
error handling in IFstream, which might not be initialized at that stage.