2.0.3
* updated to layer 31 (bot support)
* changed signature of contact_search method
2.0.2
* fixed small bugs
* added block/unblock user method
2.0.1
* store error code for last operation in TLS->error/TLS->error_code
* make interface more consitent
* deleted outdated *_ex functions
* fixed bugs 
* support for layer 28:
*   support for new pts system
*   support for new read system
*   support for passwords
*   support replies
*   support photo captions
*   support group links
1.2.1
* fixed registration/login problem
* added extension to downloads
1.2.0
* layer 22 support
