.osx: Show item info to the right of the icons on the desktop
.aliases: Add `map`

Ref. #157.
.bash_prompt: Fix `parse_git_dirty` for Git v1.8.0+

Git 1.8.0+ says “nothing to commit (working directory clean)”.
Older Git versions return “nothing to commit (working directory clean)”.

Thanks to @nicolahery in #143 for the suggestion.

Conflicts:
	.bash_prompt
.osx: Add Mac App Store section

- Move existing command to new section
- Add debug menu command

Ref. #150.

Conflicts:
	.osx