Update to 2.78.3

Upstream changes:
Version 2.78.3, January 21, 2018

    Fixed a up to 4-times performance penalty, that has been introduced in a previous version
    Brought back "Edit" to the windows context menu

Version 2.78.2, August 27, 2017

    The ran()-function is now guaranteed to return 2**30 different values

Version 2.78.1, August 13, 2017

    No more dump when using color without window open
    Processing of yabasic.xml finds hellip-entity

Version 2.78.0, January 21, 2017

    Allowed for numeric argument after break
    Fixed format of manpage (unix)
    Reworked the switch-statement, added tests

(wen)