message when project crs is changed to EPSG:3857
clean up
log also error reason when unicode decode error occurs
add settings button to add layer dialog

remove external layer definition directory edit in add layer dialog
change selection mode of tree view to ExtendedSelection
make settings dialog modal
move plugin under the web menu (fix #2)

add "move plugin to layer menu/toolbar" option
remove settings menu item
add option to turn off smooth rendering
japanese translation
make credit label smaller