Don't terminate process/script on async exception

doc/docs/api.md

@@ -209,8 +209,8 @@ onUnhandledException: ref(exn => never)
 
 When a callback called by Repromise (such as what you pass to [`wait`](#wait)) raises an exception, the exception is passed to `Repromise.onUnhandledException^`.
 
-When your program starts, `Repromise.onUnhandledException` contains a function which prints the exception, and terminates the program. Replace the reference to change this behavior.
+When your program starts, `Repromise.onUnhandledException` contains a function which prints the exception to the error log (on JavaScript) or STDERR (on native). Replace the reference to change this behavior.
 
-In the future, we will want to design a wiser approach to asynchronous exception handling. See https://github.com/aantron/repromise/issues/16 for a discussion.
+In the future, we may want to design a wiser approach to asynchronous exception handling. See https://github.com/aantron/repromise/issues/16 for a discussion.
 
 <br/>

src/js/repromise.re

@@ -9,7 +9,6 @@ type t('a) = promise('a);
 let onUnhandledException = ref(exn => {
   prerr_endline("Unhandled exception in promise callback:");
   prerr_endline(Printexc.to_string(exn));
-  exit(2);
 });
 
 

src/js/repromise.rei

@@ -54,7 +54,7 @@ module Rejectable: {
 
 
 
-let onUnhandledException: ref(exn => never);
+let onUnhandledException: ref(exn => unit);
 
 
 

src/native/repromise.re

@@ -57,7 +57,6 @@ let onUnhandledException = ref(exn => {
   prerr_endline("Unhandled exception in promise callback:");
   prerr_endline(Printexc.to_string(exn));
   Printexc.print_backtrace(stderr);
-  exit(2);
 });
 
 

src/native/repromise.rei

@@ -50,7 +50,7 @@ module Rejectable: {
 
 
 
-let onUnhandledException: ref(exn => never);
+let onUnhandledException: ref(exn => unit);