build: support linux/arm and darwin

Makefile.cross-compiles

@@ -1,8 +1,6 @@
 export PATH := $(GOPATH)/bin:$(PATH)
 export OLDGOPATH := $(GOPATH)
 export GOPATH := $(shell pwd)/Godeps/_workspace:$(shell pwd):$(GOPATH)
-export OS_TARGETS=linux windows
-export ARCH_TARGETS=386 amd64
 
 all: build
 
@@ -12,4 +10,4 @@ godep:
 	GOPATH=$(OLDGOPATH) go get github.com/mitchellh/gox
 
 app:
-	gox -os "$(OS_TARGETS)" -arch="$(ARCH_TARGETS)" ./...
+	gox -osarch "darwin/386 darwin/amd64 linux/386 linux/amd64 linux/arm windows/386 windows/amd64" ./...

cross_compiles_package.sh

@@ -14,18 +14,32 @@ make -f ./Makefile.cross-compiles
 rm -rf ./packages
 mkdir ./packages
 
-os_all='linux windows'
-arch_all='386 amd64'
+os_all='linux windows darwin'
+arch_all='386 amd64 arm'
 
 for os in $os_all; do
     for arch in $arch_all; do
         frp_dir_name="frp_${frp_version}_${os}_${arch}"
         frp_path="./packages/frp_${frp_version}_${os}_${arch}"
-        mkdir ${frp_path}
+
         if [ "x${os}" = x"windows" ]; then
+            if [ ! -f "./frpc_${os}_${arch}.exe" ]; then
+                continue
+            fi
+            if [ ! -f "./frps_${os}_${arch}.exe" ]; then
+                continue
+            fi
+            mkdir ${frp_path}
             mv ./frpc_${os}_${arch}.exe ${frp_path}/frpc.exe
             mv ./frps_${os}_${arch}.exe ${frp_path}/frps.exe
         else
+            if [ ! -f "./frpc_${os}_${arch}" ]; then
+                continue
+            fi
+            if [ ! -f "./frps_${os}_${arch}" ]; then
+                continue
+            fi
+            mkdir ${frp_path}
             mv ./frpc_${os}_${arch} ${frp_path}/frpc
             mv ./frps_${os}_${arch} ${frp_path}/frps
         fi