(flyspell-external-point-words): Consider a misspelling as found in the string

(flyspell-external-point-words): Consider a misspelling as found in the string
search if: (a) misspelling and found string lengths match, or (b) misspelling
is found as element in a boundary-chars separated longer string, or
(c) ispell-program-name is really ispell and misspelling is found as part of
a TeX string.  After successful match move beginning of search region to end
of match.  Warn about not found misspellings once the process is done.
(flyspell-large-region) Do not set ispell-parser to tex if in TeX mode.