PHP Mode for Emacs Code

(php-mode): Add commented-out c-lang-defvar statements below
commented-out c-lang-defconst.

(php-mode): Turn on necessary c-mode features with c-add-language,
like c-symbol-key.

(php-mode-modified): Resolve setting constant by
using format-time-string, but still using eval-when-compile.

ChangeLog entries for recent commits.

Use correct regular expression.

(php-beginning-of-defun-regexp): Support function
keywords like public, private per #1892662.

(php-mode): Remove definition php-mode-syntax-table
and other XEmacs bits that need to be revisited.

(php-imenu-generic-expression): Delete comment explaining Imenu,
since it's documented *correctly* in the manual.

(php-show-arglist, php-font-lock-keywords-1)
(php-font-lock-keywords-2): Replace "\\s-" for "[ \t]" in regular
expressions to maintain consistency.

Change incorrect year, "2007", in "Modified" field at top of file.
(php-mode-version-number): Mark as "alpha" release.