Remove note about sub-second support on Windows

This restriction no longer applies, and should not be noted in the
documentation for endpoints().

See #202.

man/endpoints.Rd

@@ -29,9 +29,6 @@ Valid values for the argument \code{on} include: \dQuote{us} (microseconds),
 \dQuote{hours}, \dQuote{days}, \dQuote{weeks}, \dQuote{months}, \dQuote{quarters},
 and \dQuote{years}.
 }
-\note{
-Subsecond \code{on} periods are not supported on Windows.
-}
 \value{
 A numeric vector of endpoints beginning with 0
 and ending with the a value equal to the length of