Added Castalia *.stat files

Castalia is a free plugin for Delphi since XE7. It uses *.stat files to
save statistics of the IDE usage for each project (compile time, debug
time etc.)

It is safe to delete it, and it is useless to move *.stat files between
developers (each developer has its own IDE statistics).

Delphi.gitignore

@@ -52,3 +52,6 @@
 # Delphi history and backups
 __history/
 *.~*
+
+# Castalia statistics file
+*.stat