Wrong usage of application symbol

Originally came from https://github.com/xuwupeng2000/capsitrano-scm-gitcopy/issues/33.

I'm not sure if this is NOT a Capistrano issue. But since everything used to work fine in staging before implementing scm-gitcopy into production I will post it here.

In my `deploy.rb` my application symbol is set to:

``` ruby
set :application, 'Semcoglas'
set :deploy_to, '/var/www/semcoweb'
```

I always regarded `application` as `App name`.

When I run `cap production deploy` everything works fine so far. All paths are used correctly based on the `deploy_to` symbol.

But then, when Composer is supposed to run, the path suddenly changes to `/var/www/Semcoglas` <- name of the `:application` symbol.

Of course I get a **_Could not open file: /var/www/Semcoglas/shared/composer.phar**_ error.

I tried without defining `:application` and indeed the wrong path will become `/var/www/shared/...`.

Any idea what is happening here?