enable MXEDIR to bet user-set. improve linux doc.

doc/release-checklist.txt

@@ -25,9 +25,11 @@ o build binaries
   Mac OS X
     (For Qt-4.7.3: Remove /Developers/Applications/Qt/plugins/qmltooling)
     ./scripts/publish-macosx.sh -> OpenSCAD-$VERSION.dmg
-  Linux: FIXME 32 vs. 64 bit
-    ./scripts/release-common.sh -> openscad-$VERSION.ARCH.tar.gz
-		(where ARCH is x86-64 or x86-32)
+  Linux:
+    32-bit: run on a 32-bit machine or VM
+    64-bit: run on a 64-bit machine or VM
+    ./scripts/release-common.sh -> openscad-$VERSION.x86-ARCH.tar.gz
+    (where ARCH will be detected and set to 32 or 64)
   Windows mingw cross-build: FIXME 32 vs. 64 bit
     ./scripts/publish-mingw-x.sh -> mingw32/Openscad-$VERSION.zip
                                  -> mingw32/Openscad-$VERSION-Installer.exe

scripts/setenv-mingw-xbuild.sh

@@ -12,11 +12,13 @@
 #
 
 if [ ! $BASEDIR ]; then
-	BASEDIR=$HOME/openscad_deps
+	export BASEDIR=$HOME/openscad_deps
 fi
 export OPENSCADDIR=$PWD
 export DEPLOYDIR=$OPENSCADDIR/mingw32
-export MXEDIR=$BASEDIR/mxe
+if [ ! $MXEDIR ]; then
+	export MXEDIR=$BASEDIR/mxe
+fi
 export PATH=$MXEDIR/usr/bin:$PATH
 
 echo BASEDIR: $BASEDIR
@@ -28,11 +30,8 @@ if [ ! -e $DEPLOYDIR ]; then
   mkdir -p $DEPLOYDIR
 fi
 
-if [ ! -h $DEPLOYDIR/mingw-cross-env ]; then
-	echo linking $MXEDIR/usr/i686-pc-mingw32/ to $DEPLOYDIR/mingw-cross-env
-	ln -s $MXEDIR/usr/i686-pc-mingw32/ $DEPLOYDIR/mingw-cross-env
-else
-	echo $DEPLOYDIR/mingw-cross-env is already symlinked
-fi
+echo linking $MXEDIR/usr/i686-pc-mingw32/ to $DEPLOYDIR/mingw-cross-env
+rm -f $DEPLOYDIR/mingw-cross-env
+ln -s $MXEDIR/usr/i686-pc-mingw32/ $DEPLOYDIR/mingw-cross-env