Included icvSortedHoughCirclesGradient

This method calls the icvHoughCirclesGradient method and sorts the
circles again in order of importance, using the accumulator value
Revert "Included icvSortedHoughCirclesGradient"

This reverts commit f380b792ac38225aaf9ca4b729fbf78b07c12c1d.
Updated documentation

Add note to clarify that the output vector of found circles is sorted by
descending order of centres accumulator values.

Also delete reductant lines on the HoughCircles documentation.
Updated Documentation (HoughCircles)

Rewrite the note on HoughCircles documentation to make it more clear
Merge pull request #1 from HelenWong/#3363BugFix

#3363 bug fix