Rename function to avoid duplication and confusion

Rename the virtual function OutputModule::doOpenFile() to OutputModule::reallyOpenFile().  This is being done because OutputModule had two member functions with the same name and different signatures, one of them virtual and one of them non-virtual.  The functions had the same name not because they are logically part of an overload set, but because they were written by different developers for different purposes, and the author of the later function did not notice the earlier one.  So, to avoid confusion, one of them is being renamed to something unique and more mnemonic.