Add <leader>msa to "send all" in clojure-mode

[jcf]

Not sure if there's a better mnemonic for this, but if I'm guessing right and s stands for send then send all makes some sense.

I've missed being able to refresh my namespaces via a single key binding more than anything else since I started using Spacemacs, and hope others will find this useful.

[StreakyCobra]

@jcf Can you propose this change in you PR #2317 directly?

[agzam]

I think 'cider-refresh should stay at m s x - to keep it consistent with default CIDER bindings (C-c C-x)

[d12frosted]

Ah. Looks like cider-refresh is already there. And even on master. So closing this. If some one wants to discuss changing key binding - open new issue or PR. Thanks :)