Updated emails and re-arranged scrolling screen. TW
Changed compile option -mcpu=pentium to -march=pentium.  The -mcpu= is deprecated.
bigport.h isn't used.  The information was put in port.h many years ago.
Minor changes to files found when compiling under Cygwin.  Mostly to match defines already in unix.c.
Changed the optimization from -Os to -O2.  Don't have any idea why I wanted to optimize for size.
Removed includes for code that was moved to prompts2.c.
Revised includes so that compiling with -DDIRENT will include the correct file.
Rearranged includes and added a check for FNDELAY already being defined.
Removed declaration of infinity, since it isn't used.
Added include so source would compile under Cygwin.
Added check for a prior definition of _fastcall to quiet compiler warnings.
Added ifdef so that Cygwin compile will not use long doubles.
Revised the defines for compiling under Cygwin.
Changed the merge_pathnames mode in ValidateLuts() from 0 to 3 so that Xfractint will correctly load maps such as froth3.map and altern.map that are set internal to Fractint/Xfractint when certain fractal types are selected.
Moved the XFRACT stackscreen() functions from realdos.c to video.c so that curses.h will only be needed in the unix directory.
Added ifdef so that if __cdecl is already defined, we don't try to define it again.
Modified the logic that deterimines when the grid is no longer used and the on-the-fly routine is used.  This also affects how large an image can be when using integer math.
Changed the patch number.
Added docs for version 20.4 patch 4.
Changes to start moving files from the common directory into the dos directory so that they won't be compiled under *nix.  Also separating out the dos and *nix specific prototypes in prototyp.h into their own prototype header files.