Building the Callflow

In order to visualize the attach call flow in Magma, this change adds a sequence flow diagram. The file Attach_call_flow_in_Magma.txt can be uploaded to sequencediagram.org to edit and to export the .svg. or .jpg image. The color scheme in the diagram is as follows:

• Green: State changes
• Red: Code that crosses task boundaries or modifies emm_context without a function call
• Orange: Timers and notes on which function sends out the message
• Blue: Code that can be optimized, renamed or is inconsequential in this call flow