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
This commit improves the docs for both functions (more Go-like) and
drops an unnecessary condition in IsValidBucketName. This also drops a
condition in IsValidObjectName where "" (empty string) was a valid
object name. This has been fixed and will no longer return true.
This commit also adds tests for both functions, including a regression
test for the bug fix.