flexiable the build scripts and add a freebsd build script

scripts/build_freebsd.sh

@@ -0,0 +1,27 @@
+outPlattform=freebsd
+outArch=amd64
+outPath=./output_$outPlattform_$outArch
+
+rm -rf $outPath
+mkdir $outPath
+
+CGO_ENABLED=0 GOOS=$outPlattform GOARCH=$outArch go build ../gogs.go
+chmod +x gogs
+mv gogs $outPath/
+
+cp -r ../conf/ $outPath/conf/
+cp -r ../custom/ $outPath/custom/
+cp -r dockerfiles/ $outPath/dockerfiles/
+cp -r ../public/ $outPath/public/
+cp -r ../templates/ $outPath/templates/
+cp ../cert.pem $outPath/
+cp ../CONTRIBUTING.md $outPath/
+cp gogs_supervisord.sh $outPath/
+cp ../key.pem $outPath/
+cp ../LICENSE $outPath/
+cp ../README.md $outPath/
+cp ../README_ZH.md $outPath/
+cp start.bat $outPath/
+cp start.sh $outPath/
+cp ../wercker.yml $outPath/
+cp mysql.sql $outPath/