Refactor Kemal main includes:

* `require "kemal"` loads `kemal/base` and `kemal/dsl`
* `require "kemal/base` loads only `kemal/base`

src/kemal/base.cr

@@ -116,3 +116,5 @@ class Kemal::Base
     logger.write "#{message}\n"
   end
 end
+
+require "./main"

src/kemal/main.cr

@@ -0,0 +1,58 @@
+require "http"
+require "json"
+require "uri"
+require "tempfile"
+require "./application"
+require "./base_log_handler"
+require "./cli"
+require "./exception_handler"
+require "./log_handler"
+require "./config"
+require "./exceptions"
+require "./file_upload"
+require "./filter_handler"
+require "./handler"
+require "./init_handler"
+require "./null_log_handler"
+require "./param_parser"
+require "./response"
+require "./route"
+require "./route_handler"
+require "./ssl"
+require "./static_file_handler"
+require "./websocket"
+require "./websocket_handler"
+require "./ext/*"
+require "./helpers/*"
+
+module Kemal
+  def self.application
+    @@application ||= Kemal::Application.new
+  end
+
+  def self.config
+    application.config
+  end
+
+  # Overload of `self.run` with the default startup logging.
+  def self.run(port : Int32? = nil)
+    CLI.new(config)
+
+    application.run(port)
+  end
+
+  # The command to run a `Kemal` application.
+  # The port can be given to `#run` but is optional.
+  # If not given Kemal will use `Kemal::Config#port`
+  def self.run(port : Int32? = nil)
+    CLI.new(config)
+
+    application.run(port) do |application|
+      yield application
+    end
+  end
+
+  def self.stop
+    application.stop
+  end
+end