release of new stable version

releasing new stable build of firmware version 2.8.0

releasing new daily build of firmware version 2.6.0

prepared next stable release, part II

releasing next stable mainly because of nes bootloader with LCD text …

…output

Merge pull request #834 from db4ple/cubemx-port

Definitly switching active-devel to STMicroelectronics HAL libraries.

last release build with old STM libraries

updated ui-menu-handbook

preparing testing release 1.5.6

preparing next testing