Merge changes from CPerl-5.0.

Merge changes from CPerl-5.0.
(toplevel): Require man.
(condition-case): Don't autoload tmm-prompt (it's in loaddefs.el).
(cperl-electric-backspace-untabify): New var.
(cperl-electric-backspace): Use it.
(cperl-vc-header-alist): Extract numeric version from the Id.
(cperl-build-manpage): New fun.
(cperl-menu): Use it.  Add toggle-autohelp.
(cperl-mode) <defun-prompt_regexp>: Understand prototypes.
(cperl-electric-brace): Use `cperl-after-block-p' for detection.
(cperl-electric-keyword): Make $if (etc: "$@%&*") non-electric.
'(' after keyword would insert a doubled paren.
(cperl-calculate-indent): Update syntaxification before checks.
Fix wrong indent of blocks starting with POD.
(cperl-find-pods-heres): If no end of HERE-doc found, mark to the end
of buffer.  This enables recognition of end of HERE-doc "as one types".
Require "\n" after trailing tag of HERE-doc.
\( made non-quoting outside of string/comment (gdj-contributed).
Likewise for \$.  Remove `here-doc-group' text property at start
(makes this property reliable).
Text property `first-format-line' ==> t.
Do not recognize $opt_s and $opt::s as s///.
(cperl-after-block-p): Optional arg pre-block to check for a pre-block
Recognize `continue' blocks too.
(cperl-after-expr-p): Update syntaxification before checks.  Work after
here-docs, formats, and PODs too (affects many electric constructs).
(cperl-fix-line-spacing): Allow "_" in $vars of foreach etc.
(cperl-perldoc): Use case-sensitive search.