常量字段值 (Captcha 0.0.1-RELEASE API)

net.cassite.*

net.cassite.captcha.CaptchaGen
限定符和类型	常量字段	值
`public static final String`	`ALL_ENGLISH_CHARS_AND_NUMBERS`	`"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"`