Fix Ghost from the Past issues

[oznogon]

• Fix a broken mission_timer reset on main_mission 12
• Fix a string.format that breaks commsNSA()
• Remove the bespoke distance() function and include utils.lua
• Fix typos and inconsistencies in comms strings
• Make ship refs in spawn functions local, not global
• Use the pi global defined in the bespoke find function instead of ignoring it and hardcoding 3.14