Backport revisions for the 2.70a release

d2660a07, 6e99fb04, 58c22d8f, 83f20123 + ff21f6ae, a7ed1db5. cc6b106d
7997e389, 9d4b54b4, efb48fcb, 3fc293cd, 29f359c9, 77c1d179, 92a539ec,
c626462c, f48828b6, 6452d9f0, 765d077a, 74518b28, af16d462, 8da49365,
6babbf59, f0106d29, f88776bb, ee72cba0, 467596dd, e21a7b32, eed3974d,
71a2ff12, ccf9afdd, 44d6c686, 30fdfc37, b69809c8, b0a8e4ce, bd57ec68,
3b0832dd, 2a256761, 3977b761, fb25a86f, 9bbb30bf, 51abc2be, 0ebade55,
2c0e32f4, 3deaf7df, ea01b24b, c61eb64f, f3db0389, a6fb6706, eedde311,
b66a9543, 7ff123ce, f5b79dff, 7148c977, 54a8753d, fcaa0182, 4c730010,
7a213304, 07578bed, e9a64e27, fd3de8b0, ae792e93, b7712a76 + 36006220,
d9557d01, 6d973b87, 688257d1, 4acb57a7, 95ac6bc9,

Also backported openmp changes to sculpt making it so number
of real CPU cores is used as a number of threads here.