Removed redundant functions:

sr_cancel_update_module()
sr_connection_count()
sr_get_module_info()


Renamed functions with no or minimal functionality changes:

sr_event_notif_send() -> sr_notif_send()
sr_event_notif_send_tree() -> sr_notif_send_tree()
sr_event_notif_sub_get_info() -> sr_notif_sub_get_info()
sr_event_notif_sub_modify_stop_time() -> sr_notif_sub_modify_stop_time()
sr_event_notif_sub_modify_xpath() -> sr_notif_sub_modify_xpath()
sr_event_notif_subscribe() -> sr_notif_subscribe()
sr_event_notif_subscribe_tree() -> sr_notif_subscribe_tree()
sr_oper_get_items_subscribe() -> sr_oper_get_subscribe()
sr_process_events() -> sr_subscription_process_events()
srp_log() -> srplg_log()


Added simple functions:

sr_check_module_ds_access()
sr_get_module_replay_support()
sr_get_su_uid()


Changed functions:

sr_get_context() -> sr_acquire_context() and sr_release_context()
- since the context can be changed at any point, these 2 functions lock and unlock the context lock to make sure it
is always safe to use

sr_acquire_data(); sr_session_acquire_data() and sr_release_data()
- helper functions for new sr_data_t type that is just a context-change-safe wrapper for libyang data trees, read its
documentation for more information

sr_get_module_access() -> sr_get_module_ds_access()
sr_set_module_access() -> sr_set_module_ds_access()
- with support for custom DS distinction for access permissions for each datastore was added

sr_install_module_data() -> sr_install_module2()
- separate function for setting initial module data no longer made sense and instead a new function was added for
installing modules with all the possible parameters that may be needed, while keeping the simple sr_install_module()

sr_subscription_thread_resume() and sr_subscription_thread_suspend()
- new ability to suspend and resume subscription threads


Flag changes:

removed SR_SUBSCR_CTX_REUSE
- redundant because now the [out] subscrption parameter must always be initialized to NULL on the first call
