Bugfixes

This is a list of patches that fix incorrect behavior in some situations.

The patch that introduces the new escaping scheme for identifiers also has an effect on system files, which should thus be regenerated. This is not done in these series to avoid many possible conflicts during merges. After the regeneration of system it's also necessary to fix a couple of explicit references to symbols with the old naming schemes (namely two calls to 'pm_php$globals$symbols_php' must be changed with 'pm_php$$globals$$symbols$_php').