Nearly null-merge 2.5.6

diff --cc .hgtags
index 2fd5ff63536f570af6a708d39a93c0dc49124a7c,82294f4be9d69f6bccf149fc4dfe6e6fc7c51e57..0ba8a0c4be2149270a1517b515c5740b97b0f8f4
--- 1/.hgtags
--- 2/.hgtags
+++ b/.hgtags
@@@ -112,26 -112,5 +112,28 @@@ a0a6d9909312ad9c1d844af66e9c91931b93852
  657f16582943739b906f66f7efad4014492c8b1c v2.5.5c1
  1dc91e9dd5c13a4bc2d3bb7d4b5896ab264f2325 v2.5.5c2
  7098a46f0b75e5aacfaf81d65d72e3613b023532 v2.5.5
+ a87c7b96672b69dffef64c59b56fba5bb2059b99 v2.5.6c1
+ de34c7b097e8d66b1140c211dbd61d48b31ba483 v2.5.6
 +2d0bd095c420b0711000d9be66848f6cfd972b3b v2.6a1
 +eec144917a189be11ed5efa35c6604d03bc62bcc v2.6a2
 +48e9fb0a721799877f26edaef01ac6e6029b6812 v2.6a3
 +2f2f32af8c4ee8f6598f632dc83701a20726d10a v2.6b1
 +81ec8263bd6e25c9a8855cd0ce9ae881732972be v2.6b2
 +c62862d73f9ec64d655494cf1f61443446f2dea2 v2.6b3
 +1ebb2a8cc06c94471d72b5476c2050c4d115a1aa v2.6rc1
 +525792097c6308a78a76b7b5f56bbd8a24c26acf v2.6rc2
 +95fff5a6a276520b2e7e0f75fe303f49376567a5 v2.6
 +cabf303e787aa5cd7209b40e3b2caba3ee75c5a5 v2.6.1
 +01f1ae83631ae82bd8598a11c17e3f9b3f56c38a v2.6.2c1
 +4feba09a826ba99e5b482707b3d9643eba34156f v2.6.2
 +1873542c00000c4b7ce2c7992d1f2d87f866232a v2.6.3rc1
 +00c3396d7a8c4ab4c2c841d61013a073ae921d0f v2.6.3
 +25aa90a6865b63133962dd64626c53c7b6fd47d5 v2.6.4rc1
 +ea1fdafbe4fe2458ac17287e0d6c709ed00fce5c v2.6.4rc2
 +8803c3d61da275c71cabe9e9d0274dac9902e2c0 v2.6.4
 +c9f68e42ab796a3bab4f8cf3cc69ce10503cb990 v2.6.5rc1
 +fa4630916699046357a5ac16884f3fc47bd0eaa6 v2.6.5rc2
 +99af4b44e7e490390817a597a542546d749e698e v2.6.5
 +c1dc9e7986a2a8e1070ec7bee748520febef382e v2.6.6rc1
 +e189dc8fd66154ef46d9cd22584d56669b544ca3 v2.6.6rc2
 +9f8771e0905277f8b3c2799113a062fda4164995 v2.6.6