#86 Used system header files to obtain values for system macros

[Jim Monte]

Several system macros, such as INT_MAX and FLT_MAX were being defined locally instead of using system header files to obtain them. These definitions were causing warnings when the system header was included.

Also the macro MAXPOSINT was removed since it was being defined as INT_MAX, and in its only use, INT_MAX was always the appropriate value.

[Jim Monte]

Code for this patch can be found in branch beta_jdm.

commit 8a33161432bf454260f9aa0d883fd03d2e1116d7
Date:   Mon, 9 Dec 2019 23:52:41 -0500

    Cleaned up defintions of macro constants