From Andrew Stubbs <andrew.stubbs@st.com>:

    From Andrew Stubbs  <andrew.stubbs@st.com>:
        * library/mempref.itb (MemPref::constructor): Allow the Byte Per Row
        combo box to accept arbitrary values.
        (MemPref::set_bytes_per_row): Validate the new value; reject invalid
        entries and round up to a multiple of the word size.
        (MemPref::apply): Read the value from the text box even if the user
        has not pressed return.
        (MemPref::enable_format): Ensure the bytes per row value is still valid.
        (MemPref::disable_format): Likewise.
        * library/mempref.ith (MemPref): Add $gbprlist.
        * library/help/memory.html: Update.