Fix files conflict with nautilus-dropbox 

These files conflict with nautilus-dropbox, rename them to fix.

/usr/bin/dropbox
/usr/share/applications/dropbox.desktop
/usr/share/icons/hicolor/16x16/apps/dropbox.png
/usr/share/icons/hicolor/22x22/apps/dropbox.png
/usr/share/icons/hicolor/24x24/apps/dropbox.png
/usr/share/icons/hicolor/256x256/apps/dropbox.png
/usr/share/icons/hicolor/32x32/apps/dropbox.png
/usr/share/icons/hicolor/48x48/apps/dropbox.png
/usr/share/icons/hicolor/64x64/apps/dropbox.png
/usr/share/man/man1/dropbox.1.gz