DataHandler: setIncludeStaticFile requires correct slashes

[Armin Vieweg]

The following example shows, that some extension have static typoscript, which ends with a slash and some does not.

$mainTemplate
        ->setIncludeStaticFile([
            'EXT:fluid_styled_content/Configuration/TypoScript/Static/',
            'EXT:fluid_styled_content/Configuration/TypoScript/Styling/',
            'EXT:gridelements/Configuration/TypoScript/',
            'EXT:news/Configuration/TypoScript',
            'EXT:powermail/Configuration/TypoScript/Main'
        ])

Unfortunately it is necessary to enter the absolute correct path (with or without ending slash), otherwise the entry does not appear in "Selected items" in template's Include static field.

An itemsProcFunc could unify the available values, and e.g. remove the ending slash for all items.