Use prefix with rspec-toggle-spec-and-target

With prefix argument, rspec-toggle-spec-and-target will do
find-file-other-window
Fixed doc string
Split rspec-find-spec-or-target-other-window off as a new command

* Add a dedicated keybinding
* Rewrite docstrings
Quote file paths

Fixes #77

+ Small change that allows `rspec-dired-verify-single' to use Rake.
Fix a typo and add an article
Prefer using zeus spec over zeus rake spec

Zeus appears to keep rake in the development environment, unlike zeus
spec which runs in the test environment.
Merge pull request #78 from dgtized/prefer-zeus-spec

Prefer using zeus spec over zeus rake spec
Remove outdated test file
Remove ignore lines that should be in user .gitignores
Ignore build artifacts
Use syntax highlighting of GFM
There are no expectations
Require cl-lib
Remove deprecated cl
Add cl-lib as a dependency
Correct indentation
Merge pull request #79 from CQQL/toggle-buffer

Assorted tweaks and cleanups
Add defcustom settings for:

- rspec-default-spec-command-arguments
- rspec2-default-spec-command-arguments
Use rspec-command-options variable in place of rspec-default-options function
Merge pull request #81 from ignacy/configurable-default-options

Add defcustom settings for rspec command line options