support language like Chinese, in which there is no space between words.

[wufasong]

for the languages like English, one sentence can be divided into certain number words according to space, since ' ' is the interval char between 2 words in these languages. but for Chinese, there is no space between 2 words. words are connected together. for example, "中国是一个很古老的国家". for this case, we could not divided one sentence into words by space, we should calculate the chars's width, so that we could get correct number chars to fulfill current line.