Bug 20402 – use-this-other-module deprecation warnings with "use std;"

This complete program: import std; void main() { auto sw = StopWatch(); } compiles with this output: ./x145.d(5): Deprecation: struct `std.datetime.StopWatch` is deprecated - Use std.datetime.stopwatch.StopWatch. ./x145.d(5): Deprecation: struct `std.datetime.StopWatch` is deprecated - Use std.datetime.stopwatch.StopWatch. ./x145.d(5): Deprecation: struct `std.datetime.StopWatch` is deprecated - Use std.datetime.stopwatch.StopWatch. ./x145.d(5): Deprecation: struct `std.datetime.StopWatch` is deprecated - Use std.datetime.stopwatch.StopWatch. quick fix: add the following to package.d, before the huge public import: public import std.datetime.stopwatch: StopWatch; // remove when StopWatch deprecations are removed

the deprecation warnings are gone, now StopWatch is just unidentified.