Implement pseudo functions

In IVE:

• For functions implement an additional language: Pseudo function

In DVE:

• Add information about pseudo functions (and interfaces) to the hardware library
• Add system/pseudo functions to Nodes
• Implement load/save from XML for pseudo functions
• Ignore pseudo functions for the list of bindable functions
• Add check, for all used functions in DVE check if they are connected to a pseudo function. If so, check if the pseudo function exists in the node/board.