Checking in changes prior to tagging of version 0.47.

Changelog diff is:

diff --git a/Changes b/Changes
index cafde05..e636971 100644
--- a/Changes
+++ b/Changes
@@ -1,3 +1,9 @@
+0.47
+
+    - Support PUREPERL_ONLY build
+      See the Lancaster Consensus:
+      https://github.com/sjn/toolchain-site/blob/219db464af9b2f19b04fec05547ac10180a469f3/lancaster-consensus.md#specifying-pure-perl-builds
+
 0.46

     - fixed unpacking issue on big-endian system.