Centralize the #ifdef DEBUG_ ... #endif constructs

[eyalroz]

Instead of surrounding every debug-logging with preprocessor directives, we could centralize them in one place - a wrapper for console.log() within the RemoveDupes object - and have that wrapper be aware of which DEBUG_XYZ values were set on compilation. Specifically, those could be strings in a set / entries in a dictionary, which would be looked up before actually calling console log; and the wrapper would be invoked with the relevant string.