(maint) ensure powershell module loading preference is on
(GH-153)(GH-134) Update PATH on cmd.exe

This adds a command RefreshEnv.cmd to the bin files, so that one can update
environment variables out of band. There is zero chance it will work once
chocolatey.cmd calls exit /b %ERRORLEVEL% as exiting the batch effectively
destroys any updates to local environmental changes. The way it currently
works is effectively the same as using setlocal due to the use of exit.

Since this command can be called out of band, it should be called out of
band, whenever the user wants to refresh their environment variables they
can call this. Note this only works in cmd.exe shell. There is no current way
to update a powershell session other than importing the helper functions as
a module and running Update-SessionEnvironment.
(maint) formatting
(GH-459) Fix for "Cannot find Update-SessionInformation"

Do not remove the module that you imported, it will cause errors as chocolatey
attempts to finish running after upgrading itself.
(GH-460) Fix for "Package depending on newer chocolatey is installed using existing chocolatey"

During install/upgrade force the module to be imported, which will refresh the
functions and all new commands and versions will be available when the
install is called on an item later depending on the newer version.