2019-03-26 regex cleanup

2019-03-26 regex cleanup

Problems reported by Mattias Engdegård in:
https://lists.gnu.org/r/emacs-devel/2019-03/msg01028.html
* lisp/align.el (align-rules-list):
* lisp/speedbar.el (speedbar-check-read-only, speedbar-check-vc):
* lisp/vc/diff-mode.el (diff-add-change-log-entries-other-window):
* lisp/woman.el (woman-parse-numeric-arg):
Put "-" at end of character alternatives, since a range was not intended.
* lisp/erc/erc.el (font-lock):
* lisp/mail/footnote.el (cl-seq):
Avoid duplicate character alternatives by using cl-seq API.
* lisp/mail/footnote.el (footnote--current-regexp):
* lisp/textmodes/css-mode.el (css--font-lock-keywords):
Avoid repetition of repetition.
* lisp/net/webjump.el (webjump-url-encode):
Add ~ to character alternatives, and rewrite confusing range.
* lisp/progmodes/verilog-mode.el (verilog-compiler-directives)
(verilog-assignment-operator-re):
Remove duplicate.
* lisp/progmodes/verilog-mode.el (verilog-preprocessor-re):
* lisp/textmodes/css-mode.el (css--font-lock-keywords):
Don’t escape a char that doesn’t need it.
* lisp/textmodes/picture.el (picture-tab-chars): In docstring,
do not say regexp characters will be quoted; merely say in
another way that the syntax is that of character alternatives.
(picture-set-tab-stops, picture-tab-search): Don’t attempt
to regexp-quote picture-tab-chars.
(picture-tab-search): Quote \ in picture-tab-chars for
skip-chars-backwards, which treats \ differently than
regexp character alternatives do.