196 display memory (vram) set too low to function

    Detect the display memory setting, and increase it if less than 64MB.

    On certain VirtualBox setups, the default display memory setting for
    newly imported boxes is 16MB, lower than the minimum 18MB suggested by
    VirtualBox's own graphical UI. This can cause boxes to hang on boot,
    preventing ievms.sh from configuring them and even hanging the host.