Strip Illegal XML Characters based on W3C standard

W3C has defined a set of illegal characters for use in XML . You can find info about the same here:
XML 1.0 | XML 1.1
Here is a function to remove these characters from a specified XML file:
using System;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace XMLUtils
{
class Standards
{
[...]

Quickly calculate and compare MD5 or SHA2 values

There might be situations when you might want to quickly calculate the MD5 or SHA2  values of any file or a set of files. The solution depends on what is your requirement: 1) Its a one time work and you would just want the results in a text / html file 2) You want the [...]