calc-help-prefix after calc-ext has been loaded.

* lisp/calc/calc.el (calc-create-buffer): Call 'calc-load-everything'.
(calc-always-load-extensions): Delete erroneous stanza.  (Bug#79157)

* doc/misc/calc.texi (Customizing Calc): Document the new option.
* etc/NEWS: Document the new option.
* lisp/calc/calc.el (calc-inhibit-startup-message): New option to
inhibit Calc’s startup message.
(calc): Respect the option in Calc’s startup code.
* test/lisp/calc/calc-tests.el (ert): Require ert-x for
'ert-with-message-capture'.
(calc-inhibit-startup-message): Test the new user option.

The current behavior of the functions 'calc-display-strings',
'strings', and 'bstrings' is to skip any vector containing
integers outside the Latin-1 range (0x00-0xFF).  We introduce a
custom variable 'calc-string-maximum-character' to replace this
hard-coded maximum, and to allow vectors containing higher
character codes to be displayed as strings.  The default value
of 0xFF preserves the existing behavior.

* lisp/calc/calc.el (calc-string-maximum-character): Add custom
variable 'calc-string-maximum-character'.
* lisp/calc/calccomp.el (math-vector-is-string): Replace hard-coded
maximum with 'calc-string-maximum-character', and the 'natnump'
assertion with 'characterp'.  The latter guards against the
maximum being larger than '(max-char)', but not on invalid types of
the maximum such as strings.

* test/lisp/calc/calc-tests.el (calc-math-vector-is-string): Add
tests for 'math-vector-is-string' using different values of
'calc-string-maximum-character'.

* doc/misc/calc.texi (Quick Calculator, Strings, Customizing Calc):
Add variable definition for 'calc-string-maximum-character' and
reference thereof when discussing 'calc-display-strings'.
Generalize a comment about string display and availability of 8-bit
fonts.
(Bug#78528)

2b535a9c771 ; Improve documentation of some functions in files-x.el
45cf832ac75 Fix deleting the first line of calc trail

* lisp/calc/calc-mode.el (calc-settings-file-name):
* lisp/calc/calc.el (calc-mode): Bind 'warning-inhibit-types' to
avoid lexbind cookie missing warning.

* lisp/calc/calc-trail.el (calc-trail-kill): Remove the check
preventing the removal of the first trail line, which is no
longer relevant since commit 8e1376a3912.  (Bug#77816)

* lisp/calc/calc-mode.el (calc-save-modes): Add a `lexical-binding`
cookie when it is safe.  Use `pcase-dolist` and `pp`.

* lisp/calc/calc-arith.el (calcFunc-dint):
* lisp/calculator.el (calculator-expt):
* lisp/emacs-lisp/bytecomp.el (byte-compile-unfold-bcf):
* lisp/emacs-lisp/elint.el (elint-check-defcustom-form):
* lisp/ps-print.el (ps-print-page-p):
(ps-print-sheet-p): Prefer '(evenp A)' to '(= 0 (logand A 1))' and
variations thereof.