Update to 2.77.3

Upstream changes:
Version 2.77.3, December 29, 2016

    Fixed insecure usage of strcpy
    Better logging for windows installer
    Spelling corrections

Version 2.77.2, December 17, 2016

    Fixes for coloured text under windows as reported by TheMeq
    msvcr140.dll is no longer required under Windows
    Several spelling corrections contributed by ginggs
    Updated and fixed man-page under linux

Version 2.77.1, November 13, 2016

    Adopted the MIT License for yabasic
    Switched to semantic versioning; the new schema is MajorRelease.MinorRelease.Patchlevel
    New peek$ for version, documented all peeks
    Various bugfixes
    Setup program now offers to start the demo
    Redid the development process for yabasic; you may now participate in the development of yabasic itself via github: https://github.com/marcIhm/yabasic. However, the main site for programming in yabasic is still https://www.yabasic.de

(wen)