Several enhancements and bugs

Kind of Bugs:

• It is not possible to add a speaker if he/she is not a member of the eventhub.
• It is not possible to add a coffee or lunch breaks easily. It consumes a slot for sessions.
• Sessions are not sorted by start time, it is sorted by created time.
  
• If previous session's end time is 12:45, next session cannot start at 12:45 right now. However, it is annoying to write 12:46. I believe it is a mistake. We should make it a bit more flexible.
• If I want to enter Coffee Break, it is still forcing me to fill description area for minimum 50 characters.
• In last image above, it is not possible to see exact time. It is only giving hours, not minutes.
• Session name is controlled only while creating a new session. If there is a same named session, user is informed. However, this control is not controlling while editing. So it is possible to rename 2 sessions as same name.
• As an organization owner, it is not possible to kick someone from the organization.

Enhancements:

• It is not possible understand which timezone we are organizing for while creating an event
• While adding a session into an event, end time at least should be equal to start time.
  
• May be it can be a better idea to put "duration of session" like 15mins, 30mins instead of putting an end time.
• Visual mistake. Texts come on each other.
  
• It might be better if start time of next session can be equal (at least) to previous session's end time. That will decrease # of clicks.
• May be drag&drop of sessions can be activated in the future.
• It is confusing to see start and end time. I think AM/PM statement should be added.
  

sample event: