Publisher name should not be part of extension name.

[v-pavanp]

test : #6099

• VSCode Version: 1.1.0-alpha
• OS Version: Windows10

Steps to Reproduce:

1. Launch command prompt and execute command :
   code-alpha --list-extensions or code-alpha --install-extension "cpptools"

Actual: Publisher name is preceded with the extension name and without this user can't install or uninstall extension from command prompt.
Expected: Publisher name should not be required to install and uninstall extension and it should work same like how it is working from command palette : ext install Go

Example: To install CPP extension we need to provide command like:
code-alpha --install-extension "ms-vscode.cpptools"
But from command palette we can install with : ext install cpptools

[joaomoreno]

The publisher is part of the id, it is required to uniquely identify the extension.

We will change the marketplace instructions to use the id.