#256 Segfault Crash on Big Endian machines (with patch)

[Michael Bäuerle]

prboom-plus 2.5.1.4 crashes with Segfault while loading maps with ZDoom extended nodes on Big Endian machines (tested on PowerPC).

The attached patches import the data from WAD with correct byte order.
If the target type is unsigned, the sign-extended bits are masked for machines where int is larger than 32-Bit (the Endianess-Macros return signed values).
The typecasts are there to make the target types visible.

[Michael Bäuerle]

This patch uses doom_wtoYT() for all macros.