Removed test code in Invoke-ShellcodeMSIL

There was some test code at the end of Invoke-ShellcodeMSIL that would
cause the function to execute when the script was dotsourced.
Removing Get-KernelModuleInfo

Making way for Get-NtSystemInformation. Loaded kernel module information
can be viewed with `Get-NtSystemInformation -ModuleInformation`
Added Get-NtSystemInformation

Get-NtSystemInformation is a wrapper function for
NtQuerySystemInformation. It is a swiss-army knife tool for obtaining
internal OS information. It can currently be used to query the
following: global flags, handles, objects, kernel pool allocations, and
loaded kernel modules
Removed some extraneous comments