Spack 3.5 发布，Slackware下的软件包管理

Spack 3.5 发布，该版本更新如下：

This release allows the user (through the configure script) to define arbitrary paths for the directories related to package management. It also fixes a little bug in spackcook which caused the about.txt/slack-desc installed by make.sh to be overwritten.

Spack 是一个 Slackware Linux 和它的衍生品系统的独立软件包生成工具。提供一个简单清晰、安全灵活的制作软件包，减少代码工作量。