mingw support for linux->windows cross compilation

src/scripts/mkmingw.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+
+if [ -z $APP_VERSION ]; then echo "APP_VERSION is not set"; exit 1; fi
+
+
+export PATH=$MXE_PATH:$PATH
+
+echo -n "Configuring..."
+make distclean  > /dev/null
+rm -f zec-qt-wallet-mingw.pro
+rm -rf release/
+#Mingw seems to have trouble with precompiled heades, so strip that option from the .pro file
+cat zec-qt-wallet.pro | sed "s/precompile_header/release/g" | sed "s/PRECOMPILED_HEADER.*//g" > zec-qt-wallet-mingw.pro
+echo "[OK]"
+
+
+echo -n "Building......"
+x86_64-w64-mingw32.static-qmake-qt5 zec-qt-wallet-mingw.pro CONFIG+=release > /dev/null
+make -j32 > /dev/null
+echo "[OK]"
+
+
+echo -n "Packaging....."
+mkdir release/zec-qt-wallet-v$APP_VERSION 
+cp release/zec-qt-wallet.exe release/zec-qt-wallet-v$APP_VERSION 
+cp README.md release/zec-qt-wallet-v$APP_VERSION 
+cp LICENSE release/zec-qt-wallet-v$APP_VERSION 
+cd release && zip -r Windows-zec-qt-wallet-v$APP_VERSION.zip zec-qt-wallet-v$APP_VERSION/ > /dev/null
+cd ..
+
+
+if [ -f release/Windows-zec-qt-wallet-v$APP_VERSION.zip ] ; then
+    echo "[OK]"
+
+    echo "Done. Build is release/Windows-zec-qt-wallet-v$APP_VERSION.zip"
+    echo "Package contents:"
+    unzip -l "release/Windows-zec-qt-wallet-v$APP_VERSION.zip"
+else
+    echo "[ERROR]"
+    exit 1
+fi