Log Message:
lyx: update to 2.2.2

The changes are very numerous. for the full list of changes in LyX 2.2.x,
refer to http://wiki.lyx.org/LyX/NewInLyX22

Short version of LyX 2.2 user-visible changes:
    HiDPI display support
    Qt5 support
    New text display algorithm
    Horizontal scrolling for large insets
    New separators and improved control of paragraph breaks
    Improved text color support
    Improved box dialog
    Improvements to tables
    Reworked instant preview
    Enhanced source panel
    Improved outliner and navigation menu
    Enhanced language support
    New supported languages
    New supported LaTeX commands
    Layout enhancements
    Module enhancements
    New preferences settings
    New converters