Update el-GR.js

Added greek translation for no events on the day
Update es-ES.js

Spanish translation for no event in this day
Merge pull request #134 from stevoo82/patch-2

Update es-ES.js
Merge pull request #133 from stevoo82/patch-3

Update el-GR.js
Tabs instead of spaces
Merge pull request #135 from Serhioromano/no-events-in-day-view

Languages updates