Swift4: Add additional initializer for initializing model object with properties. (#6642)

* Add addiitional files from upstream

* Remove mis-added files

* Add additional swift4 initializer for initializing model object with properties.

This change fixes this issue: https://github.com/swagger-api/swagger-codegen/issues/6641

It adds an additional initializer which allows model objects to be initialized using the properties. For exxample, if we had this model:

    "ErrorInfo": {
      "type": "object",
      "properties": {
        "code": {
          "type": "integer",
          "format": "int32"
        },
        "message": {
          "type": "string"
        },
        "details": {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      },
      "description": "Example Error object"
    },

This we generate an initializer for this model object like this:

    public init(code: Int?, message: String?, details: [String]?) {
        self.code = code
        self.message = message
        self.details = details
    }

* Add hasVars checks around initializers and re-run all scripts to re-generate

samples/client/petstore/swift4/objcCompatible/git_push.sh

@@ -0,0 +1,52 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 swagger-petstore-perl "minor update"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository. 
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=`git remote`
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git crediential in your environment."
+        git remote add origin https://github.com/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:${GIT_TOKEN}@github.com/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://github.com/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'
+