Revved the nsIUnicharInputStream IID

In an effort to prevent future random crashes from the mozdev 
spellchecker, I have revved the nsIUnicharInputStream IID so that the 
spell checker can tell at runtime if it is running against he right 
version of mozilla.

As long as the spell checker is checking for errors when calling 
NS_NewUTF8InputStream, or when doing a do_CreateInstance, then it should 
simply fail to work, instead of crashing.

I'm sorry to do this so late in the game, I just wish I had thought to 
do it as a part of the bug that originally caused the crash...this also 
means the spell checker will have to be revved once more in order to 
work with current 1.4beta binaries...

Alec