Make eldoc documentation work when point is in a function argument list.

This is a simple hack: if the first call to (gethash ...) returns nil,
then go up one level of parens (when possible) and try whatever
pattern is found there instead.
Allow `completion-at-point' to use php-extras' cached function names.

This patch defines one new function, `php-extras-completion-at-point',
and adds it locally to the `completion-at-point-functions' hook in the
php-mode hook. This allows completing PHP function names using Emacs'
normal completion system, for people without auto-complete.
Deleted trailing whitespace.
Rewritten Makefile parts.
Bumped version number.
Merge branch 'release/0.4.4' into develop
Use ":exclusive 'no" to replace extra try-completion call in completion-at-point
require thing-at-point
Use funcsummary.txt from svn.php.net to get eldoc strings
refactor loading eldoc strings
add php-extras-completion-setup
Depend on php-mode in Carton (for php-syntax-mode-table). Good or bad?
Merge branch 'simplify-completion-at-point' into develop