Cleanup comment indentation so it is easier to read

And correct a code/comment discrepancy that crept in at some point.
remove symlinked files created from Makefile.PL
add files that are symlinked
sort .gitignore
hack const-xs.inc to silence use-of-uninitialized-var warnings

Cleans up build process. It is not clear if this is a bogus warning
or what. I suspect so. Anyway, I want the build process clean so this
hackery tweaks the code.