Update C# client structure using common standards

Aligns C# project outputs more with community accepted standards and
leverges Nuget for package management.

This also moves the generated C# sample code out of the test project's
Lib folder. The output structure here was causing some issues with
maintainability (e.g. had to update test project with generated code).

(see: https://gist.github.com/davidfowl/ed7564297c61fe9ab814)
Output for a project, IO.Swagger will now look like:

    .
    ├── IO.Swagger.sln
    ├── README.md
    ├── bin
    ├── build.bat
    ├── build.sh
    ├── docs
    ├── packages
    └── src
        ├── IO.Swagger
        │   └── packages.config
        └── IO.Swagger.Test
            └── packages.config

This is a change from the Java-like src/main/csharp/IO/Swagger/etc
structure and will be a breaking change for some.

samples/client/petstore/csharp/SwaggerClient/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="YOUR_GIT_USR_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="YOUR_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'
+