emacs-idris-mode: upgrade to 0.9.15
new package: swaks, a command line SMTP tool
opkg-utils: new package

Helper scripts for use with the opkg package manager.

Upstream doesn't do releases it seems, so I'm packaging the latest git
version.
Update PhantomJS; should also fix remarkjs
Readd BtrFS-progs 3.16 for snapper build
perl-Net-CIDR: new package

Expression is generated with nix-generate-from-cpan. Then I added
platforms and maintainers.
munin: add missing dependency on 'NetCIDR'

Fixes

  munin-node[30100]: Can't locate Net/CIDR.pm in @INC (@INC contains: [...])

when using the 'cidr_allow' configuration directive.
Merge remote-tracking branch 'origin/master' into test
Merge branch 'master' of github.com:joelteon/nixpkgs into new-darwin