Backport fixes for specs on Ruby 1.9.3+

Avoid gems which dropped support for Ruby 1.8:
- activesupport (4.0.0) requires ruby (>= 1.9.3)
- rake (11.0.1) requires ruby (>= 1.9.3)

Backport 6e12d7f to fix #453.

Backport db7c955 to fix a brittle spec.

References #958

Gemfile

@@ -2,14 +2,28 @@ source 'https://rubygems.org'
 
 gemspec
 
-gem "rake", "< 11.0" if RUBY_VERSION < '1.9.3'
-
-gem "treetop", "~> 1.4.10"
-gem "mime-types", "~> 1.16"
+gem 'activesupport', '>= 2.3.6' if RUBY_VERSION >= '1.9.3'
+gem 'activesupport', '>= 2.3.6', '< 4.0.0' if RUBY_VERSION < '1.9.3'
 gem "tlsmail" if RUBY_VERSION <= '1.8.6'
+gem "mime-types", "~> 1.16"
+gem "treetop", "~> 1.4.10"
 
 gem 'jruby-openssl', :platform => :jruby
 
 # For gems not required to run tests
 group :local_development, :test do
+  gem 'rake', '> 0.8.7' if RUBY_VERSION >= '1.9.3'
+  gem 'rake', '> 0.8.7', '< 11.0.1' if RUBY_VERSION < '1.9.3'
+  gem 'rdoc', '< 5' if RUBY_VERSION < '1.9'
+  gem "rspec",      "~> 2.8.0"
+  case
+  when defined?(RUBY_ENGINE) && RUBY_ENGINE == 'rbx'
+    # Skip it
+  when RUBY_PLATFORM == 'java'
+    # Skip it
+  when RUBY_VERSION < '1.9'
+    gem "ruby-debug"
+  else
+    # Skip it
+  end
 end

spec/mail/message_spec.rb

@@ -131,6 +131,10 @@ def basic_email
 
     describe "YAML serialization" do
       before(:each) do
+        # Ensure specs don't randomly fail due to messages being generated 1 second apart
+        time = DateTime.now
+        DateTime.stub(:now).and_return(time)
+
         @yaml_mail = Mail::Message.new(:to => 'someone@somewhere.com',
                                   :cc => 'someoneelse@somewhere.com',
                                   :bcc => 'someonesecret@somewhere.com',