修正config.rapid-log.level为0时,日志级别使用默认20的bug.
补充rapid方法实现及测试.
增加array.clean方法,用于快速清空数组.

 Changes to be committed:
	new file:   src/extendProto.js
	modified:   src/rapid-core.js
	modified:   src/tools.js
	modified:   src/watcher.js
	new file:   test/test_rapidFunction.js