infinite recursion in torsocks log timestamps

If libc calls open and close in order to deal with time zones for localtime, the torsocks interception of close may lead to infinite recursion: torsocks close tries to print a log message, which needs a timestamp, which it formats with localtime, which opens the tz database and calls close when done, which tries to print a log message, which needs a timestamp...

(NetBSD's libc is an example of such a libc. Note gmtime has the same property.)

The attached patch changes timestamps to be seconds since epoch minus leap seconds, i.e. a standard POSIX clock, in order to avoid this recursion.