prepare for arm platform support

Test on Raspberry Pi 2
 system: Ubunatu mate 16.10
 gtk+-3.0
 go-1.6.2

Signed-off-by: sndnvaps <sndnvaps@gmail.com>

link_linux_arm.go

@@ -0,0 +1,14 @@
+// +build !windows
+// +build !darwin
+
+// 14 Oct 2016
+
+package ui
+
+// #cgo LDFLAGS: ${SRCDIR}/libui_linux_arm.a -lm -ldl
+// #cgo pkg-config: gtk+-3.0
+import "C"
+
+func ensureMainThread() {
+	// do nothing; GTK+ doesn't care which thread we're on so long as we don't change it after starting
+}