NSIS Installer(被NSI脚本编译出来的target)获取命令行参数

References：

http://stackoverflow.com/questions/6185982/accessing-command-line-arguments-in-nsis

http://stackoverflow.com/questions/3256140/how-to-read-a-command-line-parameter-given-to-an-uninstaller

http://nsis.sourceforge.net/Get_command_line_parameter_by_name