Isds sessions and isds context refactoring
- Added new PIMPL isds context, removed old implementation.
- Added new session with mutex.
- Added new session container as global object, removed old solution.
- ISDS wrapper was refactored and simplyfied.
- Moved login methods to separate class and simplyfied their code.
- Moved tasks interface to separate class, task refactoring.
- Small QML changing based on the isds wrapper changes.
- Fixed issue #179 (closed)
Closed #179 (closed)