src/com/chenlb/mmseg4j/Seg.java
protected int search(char[] chs, int offset, int tailLen) {
		if(tailLen == 0) {
			return -1;
		}
		CharNode cn = dic.head(chs[offset]);
		
		return search(cn, chs, offset, tailLen);
	}
protected int search(char[] chs, int offset, int tailLen) {
		if(tailLen == 0) {
			return -1;
		}
		CharNode cn = dic.head(chs[offset]);
		
		return search(cn, chs, offset, tailLen);
	}
查找chs[offset]后面的 tailLen个char是否为词.
@return 返回chs[offset]字符结点下的词尾索引号,没找到返回 -1.