Temp Workaround: System.IO.Compression fix

There is a bug in Mono's System.IO.Compression which causes ZipArchive to produce an incorrect .zip file. This results in corrupt .nupkg files which do not properly install in the IDE.
Until the mono bug is fixed, this workaround is needed to build valid .nupkg files

Author: Redth

build.sh

@@ -10,6 +10,10 @@ TOOLS_DIR=$SCRIPT_DIR/tools
 NUGET_EXE=$TOOLS_DIR/nuget.exe
 CAKE_EXE=$TOOLS_DIR/Cake/Cake.exe
 
+# BEGIN TEMP WORKAROUND
+SYSIOCOMP=$TOOLS_DIR/System.IO.Compression.dll
+# END TEMP WORKAROUND
+
 # Define default arguments.
 SCRIPT="build.cake"
 TARGET="Default"
@@ -69,6 +73,20 @@ if [ $? -ne 0 ]; then
 fi
 popd >/dev/null
 
+# BEGIN TEMP WORKAROUND
+# There is a bug in Mono's System.IO.Compression
+# This binary fixes the bug for now
+# Download System.IO.Compression if it does not exist.
+if [ ! -f "$SYSIOCOMP" ]; then
+    echo "Downloading System.IO.Compression.dll ..."
+    curl -Lsfo "$SYSIOCOMP" http://xamarin-components-binaries.s3.amazonaws.com/System.IO.Compression.dll
+    if [ $? -ne 0 ]; then
+        echo "An error occured while downloading System.IO.Compression.dll."
+        exit 1
+    fi
+fi
+# END TEMP WORKAROUND
+
 # Make sure that Cake has been installed.
 if [ ! -f "$CAKE_EXE" ]; then
     echo "Could not find Cake.exe at '$CAKE_EXE'."