Make VerifyGlyphExists compile using IntelliJ

[ghost]

Changes:

• Add reference to org.w3c.dom in pom.
• BorderPropertySet.java -- Organize imports (had compile issues without org.w3c.dom).
• VerifyGlyphExists.java -- Compare line 100 (old) and line 110 (PR); the codepoint was always 0, which looks like a bug. Other updates modernize the syntax and apply IDE-recommended changes, including try-with-resources. This closes the opened font's file stream, which is technically another bug but one that would never affect the application in practice.
• ITextFontResolver.java -- Organize imports.

[asolntsev]

@DaveJarvis Thanks. Will be released as FlyingSaucer 9.2.3