BUG: incorrect documentation

In file valueAverage.H

1. Change functionObjectName-> functionObject

2. Also, it seems resetOnRestart is compulsory input required (which is missing in documentation)

3. fieldAveage has restartOnRestart whereas valueAverage has resetOnRestart ?

4. fieldAverage -> restartOnRestart -> optional argument whereas valueAverage -> resetOnRestart -> compulsory?

@andy : Mark is looking at these