GPXIN-13: If Speed is unavailable, calculate Time Moving based on lat lon changes

If distance calculations are enabled (GPXIN-13) then the speed should be calculated once the time between trackpoints has been calculated

Commit 05af1e8 implements the basic functionality and the output appears correct

<?php
require 'GPXIngest.class.php';

$gpx = new GPXIngest();
$gpx->enableExperimental('calcDistance');
$gpx->loadFile('test.gpx');
$gpx->ingest();
echo $json = $gpx->getJSON();

However, the class is generating PHP warnings (repeatedly)

PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 701
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 776
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 475

All relate to trying to extract the modal speed

475: 		$modesearch = array_count_values($this->journeyspeeds);
701: 		$modesearch = array_count_values($this->sspeed);
776: 		$modesearch = array_count_values($this->fspeed);

I'd guess we're occasionally setting a boolean as speedint which is then pushed into fspeed and sspeed on line 427

$this->fspeed[] = $ptspeed;
$this->sspeed[] = $ptspeed;

Should be reasonably easy to sort out, but well worth double-checking where else ptspeed is used.

Dropped a debug statement in

echo "Speedstring: $speed_string (".gettype($speed_string)."), ".
"speedint: $ptspeed (".gettype($ptspeed)."),".
"dist: $dist, entryperiod: {$this->entryperiod}\n";

Looks like we're occasionally getting a double

Speedstring: 0 MPH (string), speedint: 0 (integer),dist: 0, entryperiod: 0
Speedstring: 1 MPH (string), speedint: 1 (double),dist: 12.54, entryperiod: 11
Speedstring: 1 MPH (string), speedint: 1 (double),dist: 35.688, entryperiod: 17
Speedstring: 2 MPH (string), speedint: 2 (double),dist: 165.323, entryperiod: 57
Speedstring: 2 MPH (string), speedint: 2 (double),dist: 58.918, entryperiod: 17
Speedstring: 2 MPH (string), speedint: 2 (double),dist: 51.325, entryperiod: 20
Speedstring: 1 MPH (string), speedint: 1 (double),dist: 14.79, entryperiod: 16
Speedstring: 2 MPH (string), speedint: 2 (double),dist: 29.621, entryperiod: 13
Speedstring: 1 MPH (string), speedint: 1 (double),dist: 14.438, entryperiod: 12
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703
PHP Warning:  array_count_values(): Can only count STRING and INTEGER values! in /tmp/gpx/GPXIngest.class.php on line 703

So commit f6106ed castes ptspeed to an integer

It's probably wise (for debugging purposes) to add some sort of metadata to note that the speed was auto-calculated.

Created a new array within the metadata object - AutoCalc - if the speed has been calculated from the distance calculations it will set speed to true. Used an array so that if we end up calculating other items in future we don't flood the metadata object with near identical properties.

Have marked as Complete - currently this will only happen if Distance calculations are explicitly enabled - the longer term plan though is to remove the need for explicit enabling of that functionality.