Resolve test failures and other improvements

* fix indentation for cascaded calls
* register -> as identifier ops (this solves the issue with current
  php-mode where topmost-intro is misused)
* fix indentation of inlambda (issue 29)
* support use/as statements
* restore highlighting of variables (using plain regex to accomplish
  this, this is because c-mode does no highlighting of variables, only
  of their definition - and PHP has no decl keywords for variables)