random module doc improvements

Signed-off-by: Jeremiah Corrado <[email protected]>

modules/standard/Random.chpl

@@ -25,7 +25,7 @@
     conceptual stream of random numbers of a particular scalar type. Individual
     numbers can be generated with :proc:`randomStream.next`, or an iterable
     sequence of numbers can be generated by providing a domain argument to
-    ``next``. The stream's position in it's sequence can be updated with
+    ``next``. The stream's position in its sequence can be updated with
     :proc:`randomStream.skipTo`. Additionally, there are several methods for
     generating random numbers from arrays, domains, and ranges.
 
@@ -665,8 +665,8 @@ module Random {
 
     Although parallel iteration is supported, the type itself is not
     thread-safe. In particular, it is not safe to call methods such as
-    :proc:`next` or :proc:`fill` on a ``randomStream`` from multiple tasks
-    concurrently. When multiple tasks need to generate random numbers
+    :proc:`next` or :proc:`fill` on the same ``randomStream`` from multiple
+    tasks concurrently. When multiple tasks need to generate random numbers
     concurrently, a couple of approaches can be taken (other than using a
     parallel safe lock to protect the ``randomStream``):
 
@@ -679,7 +679,7 @@ module Random {
 
       forall (r, a) in zip(rs.next(A.domain), A) do a = r;
 
-    * Create a random stream for each task:
+    * Create a random stream for each task using task-private variables:
 
     .. code-block:: chapel