Add the maven-profiler extension

This is turned off by default, but can be enabled with -Dprofile, in
which case output goes into ./.profiler.

Author: benbc

.gitignore

@@ -26,5 +26,5 @@ Thumbs.db
 .cache-main
 .cache-tests
 /cypher-shell.zip
-
 packaging/standalone/src/main/distribution/cypher-shell
+/.profiler/

.mvn/extensions.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extensions>
+    <extension>
+      <groupId>fr.jcgay.maven</groupId>
+      <artifactId>maven-profiler</artifactId>
+      <version>2.4</version>
+    </extension>
+</extensions>