Function tryCopy
If 'from' exists, then copy. Otherwise, do nothing and return false.
bool tryCopy(T1, T2)
(
T1 from,
T2 to
)
if ((is(T1 == string) || is(T1 == Path)) && (is(T2 == string) || is(T2 == Path)));
Supports Path and command echoing.
Returns
Success?