Add option to use comments instead of `#if` blocks for fake macro replacements#9

Older versions of UE4, particularly those below UE4.14, are very picky when it comes to generated headers. Wrapping a `UCLASS` with `#if 0` or `#if 1` sometimes works and sometimes doesn't. The best solution I can think of is to use `/* multi-line comments */` instead of `#if` blocks in those situations. Related: https://github.com/sbseltzer/VersionMacros/issues/8 I've verified this issue only affects UE 4.13 and lower, so this isn't particularly high priority to fix.