Use extra constants and keywords from Web Mode if available

Web Mode allows users to define a custom list of additional PHP
constants and keywords.  This patch incorporates those lists into
their PHP Mode counterparts.  However, in PHP Mode we create the lists
as constants at compile-time.  That means users who reconfigure those
lists in Web Mode will not see the changes automatically propagate to
PHP Mode.
GitHub-Issue: 100 (Unit Test)
Fix two errors with the regex for matching namespace imports

1. We need to escape all backslashes.  Specifically we need to write
‘\\s-’ instead of ‘\s-’ for matching whitespace.

2. We want to match zero or more whitespace characters, not just one
optional character.

GitHub-Issue: 100
README: Document use of Web Mode constants and keywords
Merge branch 'ejmr/web-mode-constants'

* ejmr/web-mode-constants:
  README: Document use of Web Mode constants and keywords
  Use extra constants and keywords from Web Mode if available

Conflicts:
	README.md
	php-mode.el
Change the test for Issue 100 to require correct indentation

This patch also improves the test-case by adding an example of ‘use’
inside of a class definition so that we can check for proper
indentation within that context.

GitHub-Issue: 100
Line-up multiple namespaces in a multi-line ‘use’ statement

This patch modifies all four PHP Mode styles of indentation so that
code such as

    use ReflectionMethod,
        ReflectionObject,
        ReflectionProperty;

will align the namespaces.  We do this by changing how each style
handles the ‘topmost-into-cont’ language element.  That is the
syntactical element that CC Mode uses for the second and third lines
in the example above.  Normally we want to use the function
‘c-lineup-cascaded-calls’ for those elements.  With this patch we
still try to use that function first; however, if it performs no
indentation then we attempt to use ‘php-lineup-arglist-intro’, as that
will align the namespaces.

GitHub-Issue: 100
Merge branch 'ejmr/multiline-use-statements'

* ejmr/multiline-use-statements:
  Line-up multiple namespaces in a multi-line ‘use’ statement
  Change the test for Issue 100 to require correct indentation
  Fix two errors with the regex for matching namespace imports
  GitHub-Issue: 100 (Unit Test)
Increase the version number to 1.12
Update Changelog for version 1.12