WAF: Clean out/Release/deps/uv before build

Author: ry

wscript

@@ -647,9 +647,11 @@ def uv_cmd(bld, variant):
   #
   cmd = 'cp -r ' + sh_escape(srcdir)  + '/* ' + sh_escape(blddir)
   if not sys.platform.startswith('win32'):
-    cmd += ' && if [[ -z "$NODE_MAKE" ]]; then NODE_MAKE=make; fi; $NODE_MAKE -C ' + sh_escape(blddir)
+    cmd += ' && if [[ -z "$NODE_MAKE" ]]; then NODE_MAKE=make; fi; '
+    cmd += '$NODE_MAKE -C ' + sh_escape(blddir)
   else:
     cmd += ' && make -C ' + sh_escape(blddir)
+  cmd += ' clean all'
   return cmd