afa64a60bc73a5b5b1340f9ec9daae198d49e5d2 breaks the
tarball job https://hydra.nixos.org/build/40817224/nixlog/1/raw
The problem is that there is a stdenv.cc.cc.isGNU but no corresponding
stdenv.cc.cc.isClang. The "correct" fix would be to add
stdenv.cc.cc.isClang but this is simpler.
Other nixpkgs offer cscope-emacs integration and they use package.el to
register the package. When using such package, only the cscope binary is
required.
This commit removes all references to emacs24 with the exception of
emacs24-macports. The two folders in `pkgs/applications/editors` named
`emacs-24` and `emacs-24` are consolidated to a new `emacs` folder.
Various parts in nixpkgs also referenced `emacs24Packages` (pinned to
`emacs24`) explicitly where `emacsPackages` (non-pinned) is more
appropriate. These references get fixed by this commit too.
It looks like the cpu type part of modalias might have changed, my
systems (4.4.20 and 4.7.2) show something like the following:
```
cpu:type:x86,ven0000fam0006mod003F:feature:,0000,0001,0002,0003,0004,0005,0006,0007,0008,0009,000B,000C,000D,000E,000F,0010,0011,0013,0017,0018,0019,001A,001C,002B,0034,003B,003D,0068,006F,0070,0072,0074,0075,0076,007D,0080,0081,0089,008C,008D,0091,0093,0094,0095,0096,0097,0098,0099,009A,009B,009C,009D,009E,009F,00C0,00C5,0120,0123,0125,0127,0128,0129,012A,0140
```
Update the rngd modalias rule to match this so udev properly has
systemd start rngd.