+ WIP Makefile updates to support building for OS/2
- TODO: Makefile needs SYSNAME test to detect OS/2 (Bill has asked Elbert)
+ Added "__declspec(dllexport)" (via new "TX_EXTERN" #define'd in
`tp_magic_api.h`) to public function definitions in Magic tools
- WIP: So far just "Mirror/Flip" plugin
- TODO: Add "TX_EXTERN" prefix to all other public Magic tool functions
+ Renamed long Magic tool source files to have shorter filenames
- WIP: So far just "Mirror/Flip" (`mirror_flip.c` -> `mirror_f.c`)
- TODO: Rename all other magic tool source files.
h/t Elbert Pol for providing info and some diffs!