Fix end address of ranges built by rangesFromBoundaries()

[mlocati]

Fix #64.

With this fix, the result of

$ranges = \IPLib\Factory::rangesFromBoundaries('192.168.0.1', '192.168.0.78');
echo sprintf("%-15s %-15s %-15s %-15s\n", 'ip', 'start', 'end', 'realend');
foreach($ranges as $range) {
    $range2 = \IPLib\Range\Subnet::fromString($range . '');
    echo sprintf("%-15s %-15s %-15s %-15s\n", $range, $range->getStartAddress(), $range->getEndAddress(), $range2->getEndAddress());
}

is

ip              start           end             realend        
192.168.0.1/32  192.168.0.1     192.168.0.1     192.168.0.1    
192.168.0.2/31  192.168.0.2     192.168.0.3     192.168.0.3    
192.168.0.4/30  192.168.0.4     192.168.0.7     192.168.0.7    
192.168.0.8/29  192.168.0.8     192.168.0.15    192.168.0.15   
192.168.0.16/28 192.168.0.16    192.168.0.31    192.168.0.31   
192.168.0.32/27 192.168.0.32    192.168.0.63    192.168.0.63   
192.168.0.64/29 192.168.0.64    192.168.0.71    192.168.0.71   
192.168.0.72/30 192.168.0.72    192.168.0.75    192.168.0.75   
192.168.0.76/31 192.168.0.76    192.168.0.77    192.168.0.77   
192.168.0.78/32 192.168.0.78    192.168.0.78    192.168.0.78   

[coveralls]

Coverage increased (+0.008%) to 98.419% when pulling 3763f50 on fix-rangesFromBoundaries-end-address into a2a3bdf on master.