DEV: allow for method deprecation using Discourse.deprecate

New method deprecator will ensure one log message an hour happens
for all deprecated method calls per call site

Also removes unused monkey patches to ActiveRecord::Base

spec/components/discourse_spec.rb

@@ -226,4 +226,41 @@ describe Discourse do
     end
   end
 
+  context '#deprecate' do
+
+    class FakeLogger
+      attr_reader :warnings
+      def warn(m)
+        @warnings ||= []
+        @warnings << m
+      end
+    end
+
+    def old_method(m)
+      Discourse.deprecate(m)
+    end
+
+    def old_method_caller(m)
+      old_method(m)
+    end
+
+    before do
+      @orig_logger = Rails.logger
+      Rails.logger = @fake_logger = FakeLogger.new
+    end
+
+    after do
+      Rails.logger = @orig_logger
+    end
+
+    it 'can deprecate usage' do
+      k = SecureRandom.hex
+      expect(old_method_caller(k)).to include("old_method_caller")
+      expect(old_method_caller(k)).to include("discourse_spec")
+      expect(old_method_caller(k)).to include(k)
+
+      expect(@fake_logger.warnings).to eq([old_method_caller(k)])
+    end
+  end
+
 end