Revert ":cut: remove unnecessary rescue Exceptions"

This reverts commit ff18049ca6.

This broke the AR build for every adapter:

      1) Error:
    AssociationCallbacksTest#test_dont_add_if_before_callback_raises_exception:
    Exception: You can't add a post

      2) Failure:
    QueryCacheTest#test_query_cache_doesnt_leak_cached_results_of_rolled_back_queries [/Users/senny/Projects/rails/activerecord/test/cases/query_cache_test.rb:235]:
    Expected: 1
      Actual: 0

I'm reverting to get the build green again.

activerecord/Rakefile

@@ -10,7 +10,7 @@ def run_without_aborting(*tasks)
   tasks.each do |task|
     begin
       Rake::Task[task].invoke
-    rescue
+    rescue Exception
       errors << task
     end
   end

activerecord/test/cases/associations/callbacks_test.rb

@@ -180,7 +180,7 @@ class AssociationCallbacksTest < ActiveRecord::TestCase
     assert !@david.unchangable_posts.include?(@authorless)
     begin
       @david.unchangable_posts << @authorless
-    rescue
+    rescue Exception
     end
     assert @david.post_log.empty?
     assert !@david.unchangable_posts.include?(@authorless)

activerecord/test/cases/query_cache_test.rb

@@ -235,7 +235,7 @@ class QueryCacheTest < ActiveRecord::TestCase
         assert_equal 1, Post.where(title: 'rollback').to_a.count
         raise 'broken'
       end
-    rescue
+    rescue Exception
     end
 
     assert_equal 0, Post.where(title: 'rollback').to_a.count