build: remove support for VS 2010 and 2012

They can't compile io.js anyway.

PR-URL: #156
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Bert Belder <bertbelder@gmail.com>

vcbuild.bat

@@ -106,8 +106,8 @@ ENDLOCAL
 if defined nobuild goto sign
 
 @rem Look for Visual Studio 2013
-if not defined VS120COMNTOOLS goto vc-set-2012
-if not exist "%VS120COMNTOOLS%\..\..\vc\vcvarsall.bat" goto vc-set-2012
+if not defined VS120COMNTOOLS goto msbuild-not-found
+if not exist "%VS120COMNTOOLS%\..\..\vc\vcvarsall.bat" goto msbuild-not-found
 if "%VCVARS_VER%" NEQ "120" (
   call "%VS120COMNTOOLS%\..\..\vc\vcvarsall.bat"
   SET VCVARS_VER=120
@@ -116,28 +116,6 @@ if not defined VCINSTALLDIR goto msbuild-not-found
 set GYP_MSVS_VERSION=2013
 goto msbuild-found
 
-:vc-set-2012
-@rem Look for Visual Studio 2012
-if not defined VS110COMNTOOLS goto vc-set-2010
-if not exist "%VS110COMNTOOLS%\..\..\vc\vcvarsall.bat" goto vc-set-2010
-if "%VCVARS_VER%" NEQ "110" (
-  call "%VS110COMNTOOLS%\..\..\vc\vcvarsall.bat"
-  SET VCVARS_VER=110
-)
-if not defined VCINSTALLDIR goto msbuild-not-found
-set GYP_MSVS_VERSION=2012
-goto msbuild-found
-
-:vc-set-2010
-if not defined VS100COMNTOOLS goto msbuild-not-found
-if not exist "%VS100COMNTOOLS%\..\..\vc\vcvarsall.bat" goto msbuild-not-found
-if "%VCVARS_VER%" NEQ "100" (
-  call "%VS100COMNTOOLS%\..\..\vc\vcvarsall.bat"
-  SET VCVARS_VER=100
-)
-if not defined VCINSTALLDIR goto msbuild-not-found
-goto msbuild-found
-
 :msbuild-not-found
 echo Build skipped. To build, this file needs to run from VS cmd prompt.
 goto run