Fixed assets path in luci-commotion-apps

Apps will not be advertised correctly until #44 is resolved.

To test:
1. SSH/telnet to the node and type `ls /www/luci-static`. You should not see an apps directory.
2. Type `opkg files luci-commotion-apps`. You should get the following:
/www/luci-static/commotion/code.png
/www/luci-static/commotion/equals.png
/www/luci-static/commotion/radio.png
/www/luci-static/commotion/apps_form.js
/www/luci-static/commotion/chat.png
/www/luci-static/commotion/audio.png
/www/luci-static/commotion/apps.js
/usr/lib/lua/luci/controller/commotion/apps_controller.lua
/usr/lib/lua/luci/view/commotion/apps_view.htm
/www/luci-static/commotion/x.png
/usr/lib/lua/luci/model/cbi/commotion/app_settings.lua
/usr/lib/lua/luci/view/themes/commotion/apps_apps.htm
/usr/lib/lua/luci/view/commotion/apps_settings.htm
/www/luci-static/commotion/write.png
/www/luci-static/commotion/email.png
/www/luci-static/commotion/commotion-faded2.png
/www/luci-static/commotion/calendar.png
/www/luci-static/commotion/internet.png
/usr/lib/lua/luci/view/commotion/apps_display.htm
/usr/lib/lua/luci/view/themes/commotion/apps_categories.htm
/www/luci-static/commotion/check.png
/www/luci-static/commotion/commotion-faded.png
/www/luci-static/commotion/downloads.png
/usr/lib/lua/luci/view/commotion/apps_form.htm
/www/luci-static/commotion/apps.css
/www/luci-static/commotion/bann.png
/www/luci-static/commotion/admin_apps.js
/www/luci-static/commotion/photo.png
/www/luci-static/commotion/patternizer.min.js
/usr/lib/lua/luci/view/commotion/apps_admin_display.htm

Fixes #55 

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