Add phpClass::isFinal() method and the property phpClass::isFinal

Currently, atoum does not provide any assertion about final status of a
class.
And even if using final on a class seems to be a bad practice, it's not
always the case, so having an assertion about that is interesting.
To use phpClass::isFinal() and the short version phpClass:isFinal (aka
syntaxic sugar), just do:

<?php

$this->testedClass->isFinal(); // or
$this->testedClass->isFinal; // strictly equivalent to the line above.
Improve dataset key reporting in case of failure.

Currently, if a test using a dataset provider fail, atoum display in cli
the following message ($ is the CLI prompt):

$ In file 547c9209a296c on line 547 in case '547c9209a276c', 547c9209a29d7 failed for data set #3404808712286633985 of data provider 547c9209a27e1: 547c9209a2a00

To be clear, it display the key of the dataset which fail as # following by a string if a named key is used, by a number if the key is not named.
And if it's easily readable if key are not named, it's not the case if
the key is named:

$ In file 547c9209a296c on line 547 in case '547c9209a276c', 547c9209a29d7 failed for data set #integer should be greater than 0 of data provider 547c9209a27e1: 547c9209a2a00

So, to improve readability, this commit use the [] notation for the two kind of key:

$ In file 547c9209a296c on line 547 in case '547c9209a276c', 547c9209a29d7 failed for data set [integer should be greater than 0] of data provider 547c9209a27e1: 547c9209a2a00
Merge pull request #367 from mageekguy/phpClassIsFinal

Add phpClass::isFinal() method and the property phpClass::isFinal
Add #367.
Reword changelog
Merge pull request #370 from atoum/reword-changelog

Reword changelog
Add branch-alias.
Add #376.
Merge pull request #376 from Hywan/branch-alias

Add branch-alias
Hide error when publishing report to coveralls.io fails
Merge pull request #368 from mageekguy/improveDatasetKeyReporting

Improve dataset key reporting in case of failure.
Merge pull request #377 from jubianchi/coveralls-errors

Hide error when publishing report to coveralls.io fails
Add changelog line for #368 changes
Merge pull request #371 from atoum/changelog-368

Add changelog line for #368 changes
Add changelog line for #377
Manage variadic arguments.
Test should be executed only for PHP ≥ 5.6.
Class with variadic argument should be compiled at runtime to avoid parse error with PHP version ≤ 5.6.
Factor some code
Merge pull request #381 from jubianchi/master

Add changelog line for #377