Ran dos2unix on each file to have a '\n' line-ending
replaced all tabs with 4 spaces
trimmed lines
- added extern "C" when __cplusplus is defined to cquadpack.h so the methods can be used when the header is included from a C++ file

- minor fixed so that the code compiles correctly on Visual Studio and GCC
Added a typedef for the function being evaluated that is passed as parameter. This function now also receives a void* parameter so that the user can use data stored elsewhere instead of using global variables.