Attach log file instead of appending it to description

If we don't have a log file we append the line "No log available" to
the description, otherwise we attach the log file to the jira issue.

Also don't show reporter dialog on taskbar (which otherwise shows up as question mark on Linux).
Should have picked this up before...but can this process fail? Anything file-related feels a bit dangerous while we are processing a crash...or is this only used for problem reports not involving crashes?

Anyway, I wonder whether it would be better, instead of the nested exception handler, to put a try-catch in the caller of GetLogFile...so if anything we can't handle goes wrong while trying to attach the log file, we just append something to the JiraIssue summary instead.