upgrade Rails to 3.2.17

Conflicts:
	Readme.md
	spec/fixtures/Gemfile
add ruby 2.1.1 to travis build, remove debugger

The ruby debugger appears to be incompatible with rubies > 1.9.x so for
now I'll remove it.  I'll add it back when it becomes compatible.
change homepage to caboteria github repo
update readme to show how to install rails3 branch
prepare for v0.0.3 release
update rails to 4.0.3
add rails3 instructions to readme
fix a couple of gemspec warnings

There are still a few more relating to version dependencies, but these
two were easy to fix so I thought I'd do them now.
quiet gemspec warnings, remove rubyforge link

gem was raising many warnings about version specifiers being too tight
or too loose.  It seems that it likes '~> x.y' so most of them are now
of that form.

there was a link to a rubyforge project but I couldn't find the project
so I removed the link.