Add smex- prefix to helper functions
[Refactor] parse-keymap

Use `push'. Explicitly pass the output variable `commands'.
Add compatibility with command-frequency

Set `real-last-command' like in `execute-extended-command'.
This allows command-frequency to pick up the command.
Add partial minibuffer completion

Emacs' built-in completion mechanism works well for partial completions.
Readme: Add MELPA link
Version 2.1
Add smex- prefix to save-file-not-empty-p
Merge pull request #31 from timhillgit/smex-save-file

Add smex- prefix to save-file-not-empty-p
Use `execute-extended-command` for running commands

Fixes #28
Save command history in `extended-command-history', like M-x

Fixes #30
Readme: Link to changelog right at the top
Version 3.0
Fix commit "Save command history in `extended-command-history'"
Update and rerun only when the Smex minibuffer is selected
Warn when Smex is loaded on incompatible Emacsen

Fixes #36

Thanks to Steve Purcell for suggesting this patch