RT-62847

I thought Makefile.PL on Module::Install is really slow so that I couldn't continue to use it, but by profiling I found that the bottleneck: Cwd::cwd(), which does `pwd`, instead of getcwd(3), and that Use of Cwd::getcwd() makes M::I significantly faster!
Merge pull request #17 from kevindawson/RT-62847

RT-62847