provide a more actionable message when vcvarsall.bat is missing
provide a more actionable message when vcvarsall.bat is missing

bmanikm/PowerShell,JamesWTruher/PowerShell-1,bmanikm/PowerShell,jsoref/PowerShell,TravisEz13/PowerShell,PaulHigin/PowerShell,KarolKaczmarek/PowerShell,bingbing8/PowerShell,kmosher/PowerShell,JamesWTruher/PowerShell-1,bmanikm/PowerShell,jsoref/PowerShell,KarolKaczmarek/PowerShell,jsoref/PowerShell,bmanikm/PowerShell,daxian-dbw/PowerShell,daxian-dbw/PowerShell,PaulHigin/PowerShell,TravisEz13/PowerShell,JamesWTruher/PowerShell-1,PaulHigin/PowerShell,daxian-dbw/PowerShell,PaulHigin/PowerShell,bingbing8/PowerShell,jsoref/PowerShell,JamesWTruher/PowerShell-1,KarolKaczmarek/PowerShell,kmosher/PowerShell,kmosher/PowerShell,KarolKaczmarek/PowerShell,bmanikm/PowerShell,daxian-dbw/PowerShell,KarolKaczmarek/PowerShell,bingbing8/PowerShell,TravisEz13/PowerShell,kmosher/PowerShell,bingbing8/PowerShell,TravisEz13/PowerShell,bingbing8/PowerShell,jsoref/PowerShell,kmosher/PowerShell