Introducing own prelude in Haskell files

[hanjoosten]

Currently we use the standard prelude from Haskell. However, at several places we use different libraries to do IO. This is required because we want to have UTF8 all over the place, and not having to do with any locales. We have had problems with that in the past.

The state of the code is, that we now use several (sometimes even different) implementations of IO stuff like writefile, putStrLn etc. Sooner or later, this will cause problems (I think that we have these problems even now, when we write to stdout, it is not guaranteed that it is UTF8 in all casese).

To solve this, I will create a new module in which the prelude will be made available and the correct IO functions. Then I will tell the compiler not to automatically include prelude any longer. This will force the use of our own prelude, so we can guarantee the use of UTF8.