fixes for source creation

the merging db access should be done in a better way, this approach is amazingly slow because it is fixed on the already generated souce text.

also there was no possibility to detect symbolic access to string characters

some bugs that i've found and maybe i can try to fix them if you want:

any pointer is not replaced for symbolic access
fc call is wrong created (it can't be compiled back in to step7) because the call should look like this: CALL "FC_CALLED" ( param1 := value, param2 := value, param3 := value);