content-length-range policy in postPolicy API was
not working properly handle it. The reflection
strategy used has changed in recent version of Go.
Any free form interface{} of any integer is treated
as `float64` this caused a bug where content-length-range
parsing failed to provide any value.
Fixes#3295
These messages based on our prep stage during XL
and prints more informative message regarding
drive information.
This change also does a much needed refactoring.
