Create common Makefile that automatically loads make rules on a per-OS basis.

.gitignore

@@ -3,7 +3,6 @@
 /zerotier-*
 /build-ZeroTierUI-*
 /ZeroTierUI/*.user
-/Makefile
 *.o
 .DS_Store
 .Apple*

Makefile

@@ -0,0 +1,11 @@
+# Common makefile -- loads make rules for each platform
+
+OSTYPE=$(shell uname -s)
+
+ifeq ($(OSTYPE),Darwin)
+	include make-mac.mk
+endif
+
+ifeq ($(OSTYPE),Linux)
+	include make-linux.mk
+endif