“Run examples in selected…” now runs all examples if nothing is selected.

All examples in `spec/`, to be exact.
Whitespace fixes.
Add the default .rspec
Add standard RSpec configuration
Disable random sorting of specs

Makes runner specs go forever with certain seeds (e.g. --seed 6871),
disabled until the runner will run specs in a subshell. Ref:
https://github.com/elia/rspec.tmbundle/commit/92bd792d813f79ffec8484469aa9ce3c7872382b#commitcomment-7325726
Fix the switch command

- add a default describe with type subject
Fix an edge case in the switch command
Use #system instead of #`
Expand file contents to make them more readable
Extract the “described” builder and add specs

And thanks to @noniq for forcing me to write specs and fix a couple of bugs (it was only working with rails projects).
Use `FileUtils.mkdir_p` for creating directories.
Merge branch 'elia-switch-command-fix' into master

This is basically #88, but I reordered and squashed some commits.
Fix TextMateFormatter for Ruby <= 2.1.

`CGI.h` isn’t available before Ruby 2.1.0.
Use constant instead of method.
Extract method `build_argv_from_options`
Remember `argv` everytime we run examples.
Implement “Run Again” command (⌃⌘R)
Change “Run Examples in selected …” shortcut to ⌥⇧⌘R

So we have a distinct shortcut here (⌥⌘R was shared with “Run Last Example”).
Move ⌥⌘R shortcut to “Run Again”.

“Run Again” is “Run Last Examples file” on steroids, so the shortcut belongs there.
Use attr.test.rspec scope for some commands.

This scope available since TextMate 2.0-alpha.9557. It is automatically active in projects having a `.rspec` file. So the shortcuts for “Run Again” and “Run Examples in selected …” can now be used even from non-RSpec files in such projects.