Exceptions writing to log file

[algernon-A]

Users are reporting exceptions when writing to log file (primarily contested access - antivirus perhaps? - but also other reasons, the usual slings-and-arrows of IO access). Not a problem in itself - quite expected for file IO - but the mod currently isn't catching any logfile writing exceptions and thus crashes out (usually resulting in a simulation error and inability to play the game).

[algernon-A]

Simple fix: add try..catch around all file IO operations.