fold.hypertext.heredoc.

* Asterisks are now treated (styled) as valid tag characters.
* The vertical pipe | and tilde ~ are now treated as selector characters.
(CSS namespace selector, and preceding element selector, respectively.)
* Pseudo-classes can be extended with additional simple selectors. (Not
sure if extending pseudo-elements in the same way is necessary. The CSS
specs don't seem to indicate this kind of usage with pseudo-elements.)
Useful for pseudo-classes like :not() and [to lesser extent] :lang(), but
also for some vendor-specific pseudo-classes.

by script and so goes into list of lexers.

- fixed HERE doc delimiters that start with a backslash
- better disambiguation of * operator vs typeglob
- recognition of *-referenced forms of special variables
- fixed styling of '-x' style barewords in hash keys
- improved '-bareword' lexing
- minimized style transitions for POD segments
- more promiscuous 2-part quote-like operator lexing
- better disambiguation of <inputsymbol>, allows spaces
- better disambiguation of % operator vs hashes
- fixed disambiguation after ++ or -- unary operators
- improved POD regular/verbatim styling
- added missing styling for special hash vars %+, %-
- fixed styling of &'foo-style archaic call

bug.