Remove suffixes .delphi and .fpc of units

[mdbs99]

We used a good approach to separated the code that is not equal between Delphi and FPC/Lazarus: We've been using .delphi and .fpc suffixes in some units to implement the differences between those platforms. Unfortunatelly, this approach is not good if you have the minimum amount of programmers working on one project. That means that this approach takes more time than using IFDEF conditionals.
However, I do not agree to use IFDEF anywhere. So, I'm proposing rewrite these units, merge them, and using IFDEF only in some cases at the implementation secction.

[mdbs99]

We might use delphi and fpc as suffixes for usable unit by the users instead of just pseudo-units. It is just a little mind change.