v.1.4.0

Since v.1.4.0 so5extra is distributed under the BSD-3-CLAUSE license. It means that so5extra can now be used in the development of proprietary projects for free.

Version 1.4.0 requires SObjectizer-5.7.0. Older versions of SObjectizer are not supported for so5extra-1.4.0.

New submodule so_5::extra::mchains::fixed_size added in v.1.4.0. It allows the creation of mchains with fixed capacity known at compile-time. More information about that feature can be found here.