Improved history layout, added sampledata

app/sampledata/messages.json

app/sampledata/recent_messages.json

app/src/main/res/drawable/ic_close.xml

app/src/main/res/layout/layout_history.xml

app/src/main/res/layout/layout_slider.xml

app/src/main/res/layout/widget_chatmessage_plain.xml

app/src/main/res/layout/widget_history_message.xml