Add org.gtk.test.gschema-simple

Gives a good idea of how the simple schema format looks like right now.

gio/tests/org.gtk.test.gschema-simple

@@ -0,0 +1,39 @@
+schema org.gtk.test:
+  gettext-domain test
+  path /tests/
+
+  key greeting = @s "Hello, earthlings"
+    l10n: messages
+    Summary: A greeting
+    Description: Greeting of the invading martians
+  key farewell = @s "So long"
+    l10n: messages
+
+  child basic-types:
+    key test-boolean = @b true
+    key test-byte = @y 25
+    key test-int16 = @n -1234
+    key test-uint16 = @q 1234
+    key test-int32 = @i -123456
+    key test-uint32 = @u 123456
+    key test-int64 = @x -123456789
+    key test-uint64 = @t 123456789
+    key test-double = @d 123.456
+    key test-string = @s "a string, it seems"
+    key test-objectpath = @o "/a/object/path"
+
+  child complex-types:
+    key test-tuple = @(s(ii)) ("one",(2,3))
+    key test-array = @ai [0,1,2,3,4,5]
+
+  child localized:
+    gettext-domain glib20
+
+    key error-message = @s "Unnamed"
+      l10n: messages
+
+  child binding:
+    key bool = @b false
+    key int = @i 0
+    key double = @d 0
+    key string = @s ""