M-q (edit:fill-paragraph) should be better at finding the end of a sentence

[jgross@mit.edu]

As discussed on zephyr, M-q should DTRT on (sentences in parentheses.), ("quoted sentences in parentheses."), etc.

According to ​http://www.gnu.org/software/emacs/emacs-lisp-intro/html_node/sentence_002dend.html, emacs uses a regular expression like "[.?!][]\"')}]*\\($\\|\t\\|␣␣\\)[\n]*" (where ␣ is a space). Evaluating (sentence-end) on my computer gives me "\\([.?!][]\"'”)}]*\\($\\|[  ]$\\|\t\\|[  ][  ]\\)\\|[。．？！]+\\)[  \t\n]*" (where one of each of the doubled spaces is a non-breaking space).