PureBasic : Système"LTS" à partir de la version 5.20

We won't do a 5.12 as the 5.20 dev is in heavy progress, but for the next release, we will introduce a new 'LTS' system, like Ubuntu. So the 5.20 will be supported during 2 years, only bug fixes will be applied to that version, so long term projects can be based on LTS versions and switch from one to another (we plan to introduce a clear update plan from one LTS to another if some API changes). In between, we will still release other new versions, which introduce new features, and once the 2 year mark has been reached, it will be a new LTS and the old one won't be supported anymore. Please note than this new support will be in test at first, if it's too complicated for us to maintain 2 differents branchs, we could drop it. But at least we will have give it a try. It should answer some complains about upgrading the code too often when doing commercial projects.