Bug fixes and improvements

- Source code cleanup
- Functionalities for different networks were distributed in
corresponding controllers
- Module key of social sysfolder changed to "mxsocial"
- Optimized usage and generation of main module group
- FacebookGetTask: Automatically clears cache if new posts where added
by scheduler-task
- FacebookGetTask: Increased interval buffer to 86400s
- FacebookGetTask: Added static var to set api limit param