Installer warning if old node version

From @mroeder

At first I installed the Lively Kernel Scripts App one somewhere in between state of "I have nothing" and "I have successfully installed it" with the App (meaning I had some version of Node.JS, git and lively-kernel-scripts installed already). After a problem-free installation of the app, I found out that the app was using my old lk-scripts and its repository to work with. Also the app did not seem to work - update workspace/PartsBin: nothing happened. So I uninstalled the app, uninstalled the lk-scripts I had before and gave it a second try.
Second successful installation and now it was using the workspace and PartsBin that should have been installed and use the first time as well. But still, the app did not work: None of the commands was working and so I was debugging again. Calling the lk script from the command line seemed to do the job. When I was doing it as root. So I checked for my Node.JS version - it was 0.6.x - and uninstalled that one, installed the latest one (0.8.x) and updated my node modules. Afterwards it worked like a charm.

Suggestion: Maybe the installer should warn you if you have an old Node.JS version and suggest updating it. I did not find a hint on what version is need anywhere :-/.

首先定位安装程序的入口点，并检查它如何检测或使用已安装的 Node.js 版本。根据项目当前的要求确认支持的最低版本，然后让安装程序在用户的版本过旧时发出警告，并建议他们更新。