travis: Rakefile problems

It would seem that ruby1.8.7 on Travis doesn't like rdoc/task nor
rake/rdoctask, and exits violently if you try to require rake/rdoctask.
Add build status to README
Fixes for Windows with ruby1.9

* Added packaging instructions
* Disabled localization... does more harm than good.
Properly recover from bad (old?) Marshal files
Reverted in-git version to "[git]"

Other version numbers should only be set for actually-released versions
documentation: Additional required gems
No longer require external rubygems