Fixed a bug in prefixing properties

I fixed a bug that PrefixFree works incorrectly when a CSS rule misses '`;`' but has a name with a property keyword (this usually happens after compressing the CSS file).

**Bug reproduce:**
`#one{transition:all .2s linear}.transform{}#another{display:block;}`
`#one{transition:all .2s linear}#user-select{}#another{display:block;}`

will be rendered to the followings (Firefox/Webkit/Opera):

`#one{-moz-transition:all .2s linear}.-moz-transform{}#another{display:block;}`
`#one{-moz-transition:all .2s linear}#-moz-user-select{}#another{display:block;}`