Rename object.edit -> object.ls.edit.

The old way often conflicted with Rails controller conventions.
Symbols are more conventional with #edit.
Add travis badge to README.

h.t. @mogox
Looksee.rename now simply takes the new name for :ls.

LOOKSEE_METHODS is now also LOOKSEE_METHOD and simply specifies a single name.
Raise informative exceptions when #edit fails.
Ruby 2.1 support.
Tone down the self-promotion.
Bump rspec.
Move dev dependencies into Gemfile.
Gitignore .bundle.
Use :platform to declare debugger dependencies.
Remove ObjectSpace dependency in specs.

Doesn't seem to work with JRuby 1.7 unless run with -X+O, even if
JRuby.objectspace is set to true.
Don't capture stderr when testing wirble compatibility.

The JVM dumps crap on stderr if JAVA_TOOL_OPTIONS is set, e.g.
Don't need absolute path when running irb through bundler.
Load rubysl on rbx when running through bundle exec.
Update changelog.
Update travis rubies.