Add Ctrl+End/Ctrl+Home emulation in cmd mode

Ctrl+End deletes to end of line
Ctrl+Home deletes to start of line

Neither puts deleted text in the clipboard/kill ring.
Read PowerShell history into PSReadline on import

Added a public api to add command lines to PSReadline history.
Use this api when the module is loaded so people that
persist their history can recall those command lines without
any additional changes to their profile.