We also start carrying the previous versions as crystal is under rapid
development.
Instead of pulling the binary builder each time, create a derivation that we can
use to build the various versions.
Due to https://github.com/crystal-lang/crystal/issues/4719,
when building Crystal with LLVM 4 with debug infos from prebuilt binary (w/ LLVM 3.8) will always be failed.
The temporary solution is to build a LLVM 4 version without debug info,
then use it to build Crystal with debug info on LLVM 4.
This will cause building phrase going longer then normal.
We can remove this hack after Crystal fix the issue.
* pkgs: refactor needless quoting of homepage meta attribute
A lot of packages are needlessly quoting the homepage meta attribute
(about 1400, 22%), this commit refactors all of those instances.
* pkgs: Fixing some links that were wrongfully unquoted in the previous
commit
* Fixed some instances
