Gyp checks for VS IDE existence, but not does validate that the C++ compiler is installed

What steps will reproduce the problem?

1. Install Windows with VS 2010 Shell (Isolated) -- this is used by partner 
tools who want to use the IDE with their own compiler, such as Atmel Studio 
(http://www.atmel.com/microsite/atmel_studio6/)
2. Install a newer Visual Studio including C++, such as VS 2013 Ultimate.
3. Try to compile with Gyp and msvs_version=auto.  It will detect 'devenv' for 
VS 2010 and generate 2010 c++ build files.

What is the expected output? What do you see instead?

I expect the VS 2013 C++ compiler to be invoked, instead I see:

  The build tools for Visual Studio 2010 (Platform Toolset = 'v100'

What version of the product are you using? On what operating system?

node-gyp 12.2 which embeds gyp ~R1781

Please provide any additional information below.

Recommended fix is to check for the existance of cl.exe rather than devenv.exe 
since you can install Visual Studio without C++ in multiple ways, so the 
presence of devenv.exe alone is not enough to determine that this C++ toolset 
is present.

Original issue reported on code.google.com by j...@hikinghomeschoolers.org on 15 Feb 2014 at 8:12

Corky94 / gyp

Gyp checks for VS IDE existence, but not does validate that the C++ compiler is installed #407