ie8_tls12: new verb

[alessivs]

This verb adds TLS 1.1 and TLS 1.2 support for IE 8, configurable through the UI in Tools : Internet Options : Advanced.

Changes to the configuration affect the registry value at:

• HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\SecureProtocols

Any configuration made prior to installing this verb influences the initial value, so the verb doesn't concern itself with modifying the registry to enable the new protocols without user interaction.

Also, the UI (IE 8 menu bar) isn't visible with the Windows 7 setting, so this verb doesn't issue a final w_set_winver 'default' invocation. FWIW the menu bar isn't the only part of IE's UI that breaks with that setting.

Before enabling both protocols

After enabling both protocols

Added: As discussed in #1593 (comment)