Language of the installer and language of the installed help files are two
separate things. It was not good that they were handled in the same array.
Now all help packs has English + localized installer.
Only en.US help pack isntalls en-US help.
Also, maintaning the list of languages, that are not supported by Windows,
is pointless. What Windows? Windows 8 supports a lot more than Windows XP.

Change-Id: I075a18648796a42609329ead9e8e6a9da9c1fef3