illumos gate

With boot loader environment being passed to kernel, we do not need to build complex kernel command line for MB2 kernel, instead all automatic properties should be passed in environment and only manually set properties should be set on kernel command line.

so this will set kernel command line:

     ok boot -B console=ttya

but

     ok boot

will keep variables in environment. However, there is one notable exception - if the user did not specify console like above, but there is os_console set in environment, we will pass the "-B console=$os_console" for kernel command line. This exception is because of the nature of os_console variable itself - it was created to distinguish loader console from kernel console.

For multiboot 1 kernels, there are no changes - all properties are set on kernel command line.