Start using 'mu' for Gmail

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Start using powerline

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Change 'browse-kill-ring key binding

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add Slime REPL helper commands
Small comment change

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>