feat: support multi-lines environment variables substitution

  it will then be possible to mask it and the template will automatically decode it prior to using it.

3. Don't forget to escape special characters (ex: `$` -> `$$`).

### Environments configuration

As seen above, the Cloud Foundry template may support up to 4 environments (`review`, `integration`, `staging` and `production`).

| `CF_PROD_ENVIRONMENT_URL`      | The production environment url **including scheme** (ex: `https://my-application.public.domain.com`) Do not use variable inside variable definition as it will result in a two level cascade variable and gitlab does not allow that. | _none_ |

| `CF_PROD_RETIRED_APP_SUFFIX` | If set, the app old version is not deleted/overriden but renamed with this suffix | _none_ |

### Hook scripts

Deployment jobs also support _optional_ **hook scripts** from your project, located in the `$CF_SCRIPTS_DIR` directory 

    * remind to delete your review env **manually before deleting the branch**

    * otherwise you'll have to do it afterwards from your computer (using `cf` CLI) or from the Cloud Foundry console.

### Manifest processing

Deployment jobs support a versatile way to evaluate the **deployment manifest**.

* merged with file `cf-vars-$env.yml` if present in your project (e.g. `cf-vars-staging.yml` for staging environment).

* or merged with file `cf-vars.yml` if present in your project **and no `cf-vars-$env.yml` file was found**.

:warning: your `cf-vars-$env.yml` or `cf-vars.yml` files **may** contain variable patterns such as `${MY_SECRET}`. If so, those patterns will 

be evaluated (replaced) with actual environment values. This is a safe way of managing your application secrets.

:warning: your `cf-vars-$env.yml` or `cf-vars.yml` files **may** contain variable patterns such as `${MY_SECRET}`.

If so, those patterns will be evaluated (replaced) with actual environment values.

Multiline variables must be surrounded by **double quotes** (`"`).

This is a safe way of managing your application secrets.

### Routes management

    done

  }

  function awkenvsubst() {

    awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);val=ENVIRON[var];gsub(/["\\]/,"\\\\&", val);gsub("\n", "\\n", val);gsub("\r", "\\r", val);gsub("[$]{"var"}",val)}}1'

  }

  function pre_push() {

    # maybe execute pre push script

    prescript="$CF_SCRIPTS_DIR/cf-pre-push.sh"

    if [[ -f "${envvarfile}" ]]

    then

      log_info "--- variables file for env \\e[33;1m${env}\\e[0m (\\e[33;1m${envvarfile}\\e[0m) found"

      envsubst < "$envvarfile" >> "$targetvarfile"

      awkenvsubst < "$envvarfile" >> "$targetvarfile"

    elif [[ -f "${globvarfile}" ]]

    then

      log_info "--- global variables file (\\e[33;1m${globvarfile}\\e[0m) found"

      envsubst < "$globvarfile" >> "$targetvarfile"

      awkenvsubst < "$globvarfile" >> "$targetvarfile"

    fi

    log_info "--- manifest variables:"