merge 3.1 (with 3.1.5rc1 release tag)

diff --cc .hgtags
index 9ccde1e10e600ece08bfe415985cc33d84391c4d,71d5cc9234d26b71ab9a9101a6a8f241573dc8c1..7ac43b0804317a76f79bcb195e26a143d1c5ac72
--- 1/.hgtags
--- 2/.hgtags
+++ b/.hgtags
@@@ -77,19 -77,4 +77,20 @@@ d18e9d71f369d8211f6ac87252c6d3211f9bd09
  a4f75773c0060cee38b0bb651a7aba6f56b0e996 v3.1.3
  32fcb9e94985cb19ce37ba9543f091c0dbe9d7dd v3.1.4rc1
  c918ec9f3a76d6afedfbb5d455004de880443a3d v3.1.4
+ ee26aca3219cf4bb0b93352e83edcc9cb28c7802 v3.1.5rc1
 +b37b7834757492d009b99cf0ca4d42d2153d7fac v3.2a1
 +56d4373cecb73c8b45126ba7b045b3c7b3f94b0b v3.2a2
 +da012d9a2c23d144e399d2e01a55b8a83ad94573 v3.2a3
 +d92a5b850f5e56808bedc01723906ed64c5e6e2e v3.2a4
 +b635cea94195780c8716e236479af319bcc26253 v3.2b1
 +e3af5f3a7904c0d5343ec9633ea66e7acfd23a66 v3.2b2
 +865d5b24bf28ca41b536befc326407c03e74a4d5 v3.2rc1
 +acf3e24dd0d0dfd1e20c907d696d3da965a8f56f v3.2rc2
 +18c1f52896501c7ee13b038454a39acb45a87979 v3.2rc3
 +a222a015e28d8ae9af3899258dc6c15c3d40add0 v3.2
 +8ffac2337a3323323d02153ac919fd1483176652 v3.2.1b1
 +cfa9364997c7f2e67b9cbb45c3a5fa3bba4e4999 v3.2.1rc1
 +5df549718fb4841ff521fe051f6b54f290fad5d8 v3.2.1rc2
 +ac1f7e5c05104d557d5acd922e95625ba5d1fe10 v3.2.1
 +c860feaa348d663e598986894ee4680480577e15 v3.2.2rc1
 +137e45f15c0bd262c9ad4c032d97425bc0589456 v3.2.2