Support Prefix and Suffix.

#5
4 new methods:

https://github.com/daimajia/NumberProgressBar/blob/master/library%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdaimajia%2Fnumberprogressbar%2FNumberProgressBar.java#L398-L420

Set Progress Text Invisible

v1.1

Visibility

Android NumberProgressBar Born

v1.0

Born