Fix problems reported by PMD static code analysis

[pilafmon]

Item	File	Line	Problem
1	src/HashMapLoop.java	5	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
2	src/HelloWorld.java	3	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
3	src/TopMultiMap.java	21	Deeply nested if..then statements are hard to read
4	src/WebPageReader.java	6	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
5	src/XmlReader.java	8	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
6	src/XmlValidator.java	9	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
7	src/XmlWriter.java	13	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
8	src/library/BareBonesBrowserLaunch.java	20	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
9	src/library/BareBonesBrowserLaunch.java	58	New exception is thrown in catch block, original stack trace may be lost
10	src/library/DesktopBrowser.java	3	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.
11	src/library/LaunchBrowserApp.java	5	All methods are static. Consider using a utility class instead. Alternatively, you could add a private constructor or make the class abstract to silence this warning.