On Windows systems the timer may not be accurate enough to measure
the time between init() and done(). Avoid computing statistics with
a diff time of 0 in such cases.
Fixes#2230.
The PHP scripts need to know the position of the nominatim
tool in order to call it. This is handed in as environment
variable, so it can be set by the Python script.
Wait for 2 seconds before logging the first progress, so that we
have numbers that are a bit more reliable statistically speaking.
Also provides an actual implementation for the log_interval
parameter and fixes some small style issues.
