* eword-decode.el: Change the way to decode successive encoded-words:

* eword-decode.el: Change the way to decode successive encoded-words:
 decode B- or Q-encoding in each encoded-word, concatenate them, and decode it
 as charset.  See the following threads for more information:
 http://news.gmane.org/group/gmane.emacs.pretest.bugs/thread=9541
 http://news.gmane.org/group/gmane.emacs.gnus.general/thread=61176
(eword-decode-allow-incomplete-encoded-text): New variable.
(eword-decode-encoded-words): New function.
(eword-decode-string): Use it.
(eword-decode-region): Use it.
(eword-analyze-encoded-word): Use it.
(eword-decode-encoded-word): Abolish.
(eword-decode-encoded-text): Abolish.
(eword-decode-encoded-word-error-handler): Abolish.
(eword-warning-face): Abolish.
(eword-decode-encoded-word-default-error-handler): Abolish.