Disable :show_exceptions on Base in all environments

See http://tinyurl.com/l7lvnl for ML discussion on this.

lib/sinatra/base.rb

@@ -941,7 +941,7 @@ module Sinatra
     set :raise_errors, true
     set :dump_errors, false
     set :clean_trace, true
-    set :show_exceptions, Proc.new { development? }
+    set :show_exceptions, false
     set :sessions, false
     set :logging, false
     set :methodoverride, false
@@ -1012,6 +1012,7 @@ module Sinatra
   # Base class for classic style (top-level) applications.
   class Default < Base
     set :raise_errors, Proc.new { test? }
+    set :show_exceptions, Proc.new { development? }
     set :dump_errors, true
     set :sessions, false
     set :logging, Proc.new { ! test? }

test/options_test.rb

@@ -183,10 +183,15 @@ class OptionsTest < Test::Unit::TestCase
   end
 
   describe 'show_exceptions' do
+    %w[development test production none].each do |environment|
+      it "is disabled on Base in #{environment} environments" do
+        @base.set(:environment, environment)
+        assert ! @base.show_exceptions?
+      end
+    end
+
     it 'is enabled on Default only in development' do
       @base.set(:environment, :development)
-      assert @base.show_exceptions?
-
       assert @default.development?
       assert @default.show_exceptions?