games/warzone2100: Misc automated cleanups.

Signed-off-by: David Somero <xgizzmo@slackbuilds.org>

games/warzone2100/warzone2100.SlackBuild

@@ -24,10 +24,19 @@
 
 PRGNAM=warzone2100
 VERSION=${VERSION:-2.3.0}
-ARCH=${ARCH:-i486}
 BUILD=${BUILD:-1}
 TAG=${TAG:-_SBo}
 
+# Automatically determine the architecture we're building on:
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) ARCH=i486 ;;
+    arm*) ARCH=arm ;;
+    # Unless $ARCH is already set, use uname -m for all other archs:
+       *) ARCH=$( uname -m ) ;;
+  esac
+fi
+
 CWD=$(pwd)
 TMP=${TMP:-/tmp/SBo}
 PKG=$TMP/package-$PRGNAM
@@ -43,8 +52,8 @@ elif [ "$ARCH" = "x86_64" ]; then
   SLKCFLAGS="-O2 -fPIC"
   LIBDIRSUFFIX="64"
 else
-  echo "Unrecognized architecture type! Check the script: $0"
-  exit 1
+  SLKCFLAGS="-O2"
+  LIBDIRSUFFIX=""
 fi
 
 set -e