Non-styled versions of TTF fonts are chosen and artificially styled over available styled versions

Describe the bug

I'm observing something similiar to what #244 described: I'm registering a bunch of TTF files (Roboto) in different styles from the class path and trying to use these. However, OpenPDF seems to choose the regular (non-styled) font file and apply all necessary styles to it instead of using the styled version in the first place.

To Reproduce

Put the Roboto files (regular, italic, bold, bold-italic; downloadable from Google Fonts) onto the classpath (e.g., the resources folder when using maven) and register them like so:

// In a class file

private static final Font ROBOTO_BOLD_ITALIC;
private static final Font ROBOTO_BOLD;
private static final Font ROBOTO_ITALIC;
private static final Font ROBOTO_REGULAR;

static {
    URL robotoRegularUrl = Thread.currentThread ().getContextClassLoader ().getResource ("fonts/Roboto-Regular.ttf");
    URL robotoBoldUrl = Thread.currentThread ().getContextClassLoader ().getResource ("fonts/Roboto-Bold.ttf");
    URL robotoItalicUrl = Thread.currentThread ().getContextClassLoader ().getResource ("fonts/Roboto-Italic.ttf");
    URL robotoBoldItalicUrl = Thread.currentThread ().getContextClassLoader ().getResource ("fonts/Roboto-BoldItalic.ttf");

    // Obviously check if any of those URLs is null

    try {
        FontFactory.register (robotoBoldItalicUrl.toExternalForm (), "Roboto-BoldItalic");
        FontFactory.register (robotoItalicUrl.toExternalForm (), "Roboto-Italic");
        FontFactory.register (robotoBoldUrl.toExternalForm (), "Roboto-Bold");
        FontFactory.register (robotoRegularUrl.toExternalForm (), "Roboto");

        ROBOTO_BOLD_ITALIC = FontFactory.getFont ("Roboto-BoldItalic", BaseFont.IDENTITY_H, true, 10, Font.BOLDITALIC);
        ROBOTO_BOLD = FontFactory.getFont ("Roboto-Bold", BaseFont.IDENTITY_H, true, 10);
        ROBOTO_ITALIC = FontFactory.getFont ("Roboto-Italic", BaseFont.IDENTITY_H, true, 10);
        ROBOTO_REGULAR = FontFactory.getFont ("Roboto", BaseFont.IDENTITY_H, true, 10);
    } catch (Exception e) {
        e.printStackTrace ();
        throw new IllegalStateException (e);
    }
}

This will lead to all files being read. Using them like new Paragraph ("text", ROBOTO_BOLD_ITALIC); will (apparently) not use the file previously read, but rather the regular one and OpenPDF will apply all given styles to that one. This is judging by the looks of the outcome, it looks just like the PDF displayed in #244.

Curiously, if I don't specify styles at all in FontFactory.getFont, then OpenPDF will only use ROBOTO_REGULAR whenever ROBOTO_ITALIC or ROBOTO_BOLD_ITALIC should have been used. ROBOTO_BOLD works as expected though.