Squashed 'third_party/boostorg/property_tree/' content from commit bdfe275

Change-Id: I075a5e242aaddc356ecc81e756c4a0907fc38130
git-subtree-dir: third_party/boostorg/property_tree
git-subtree-split: bdfe275d172ac30bc5e89a6375a5a64dea20b3c0
diff --git a/examples/settings_partially-existent.info b/examples/settings_partially-existent.info
new file mode 100644
index 0000000..ed5e8c2
--- /dev/null
+++ b/examples/settings_partially-existent.info
@@ -0,0 +1,6 @@
+settings
+{
+	setting1 15
+	;setting2 9.876						// non-existent
+	;setting3 Alice in Wonderland		// non-existent
+}