Additional support for Intel compilers

[john@…]

There are two issues here:

1) When building without a user-config.jam and with --toolset=intel then the intel compiler does not appear on the command line at all, and cmd.exe tries to execute the response file.

2) Auto-config support could be better, on Windows the Intel compilers can be detected by looking at HKEY_LOCAL_MACHINE\SOFTWARE\Intel\Compilers\C++\$version$\$arch$ and getting the value "ProductDir".

$version$ is the compiler version: 80 (for 8.0), 91 (for 9.1) or 10.0.XXX for version 10.0 where XXX is the patch level.

$arch$ is the architecture: "IA32" is the only one I have installed, but there are others for sure.

HTH, let me know if you need testing help.

John.