glapi: Move to src/mapi/.

Move glapi to src/mapi/{glapi,es1api,es2api}.
diff --git a/src/SConscript b/src/SConscript
index cf6db73..b72491d 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -1,6 +1,7 @@
 Import('*')
 
 SConscript('glsl/SConscript')
+SConscript('mapi/glapi/SConscript')
 
 if 'mesa' in env['statetrackers']:
     SConscript('mesa/SConscript')