compose: Never hide send button.

`Press Enter to send` used to hide `Send` button, we remove that
behaviour.

We show the current state of `Enter` hotkey action via text below
`Send` button which can toggle behaviour on click.

tools/lib/capitalization.py

@@ -168,6 +168,9 @@ IGNORED_PHRASES = [
     r"University of California San Diego",
     # Used in stream creation form
     r"email hidden",
+    # Use in compose box.
+    r"to send",
+    r"to add a new line",
 ]
 
 # Sort regexes in descending order of their lengths. As a result, the