Prepare release 4.8.0

CHANGELOG

@@ -1,3 +1,6 @@
+Version 4.8.0 - 2018-04-23
+* Bug fixes (see mercurial logs for details)
+
 Version 4.6.0 - 2017-10-30
 * Bug fixes (see mercurial logs for details)
 

COPYRIGHT

@@ -1,4 +1,4 @@
-Copyright (C) 2016-2017 B2CK.
+Copyright (C) 2016-2018 B2CK.
 Copyright (C) 2016-2017 Nicolas Évrard.
 
 This program is free software: you can redistribute it and/or modify

tryton.cfg

@@ -1,5 +1,5 @@
 [tryton]
-version=4.7.0
+version=4.8.0
 depends:
     ir
     res