Log coordinates of invalid pipes

Based on Maeyanie's fix for the old BC2 Bukkit port:
https://github.com/Maeyanie/BuildCraft/commit/7dac7f9c2afec2b1f2935458a7bda6838b9b893c
Add more feedback to the 'invalid pipe' loading errors.
Merge pull request #560 from agaricusb/pipelog

Log coordinates of invalid pipes