Explicitly enable access to web cron script

See issue http://forum.piwik.org/read.php?2,109382
Update .htaccess
Allow just archive.php
Preventing random build issue: https://travis-ci.org/piwik/piwik/jobs/23912449
Merge pull request #266 from piotr-cz/patch-1

Explicitly enable access to web cron script
Prevent some random build failures when connectivity fails, by calling travis_retry which retries up to 3 times

https://travis-ci.org/piwik/piwik/jobs/23570274
https://travis-ci.org/piwik/piwik/jobs/23912462
http://blog.travis-ci.com/2013-05-20-network-timeouts-build-retries/
Updating comment to reference to ./console core:archive instead of archive.php
Prevent some random build failures when connectivity fails, by calling travis_retry which retries up to 3 times

https://travis-ci.org/piwik/piwik/jobs/23570274
https://travis-ci.org/piwik/piwik/jobs/23912462
http://blog.travis-ci.com/2013-05-20-network-timeouts-build-retries/
ref #3838 unnecessary code
refs #3838 split view into partial templates
Composer update of symfony/console
Merge branch 'master' of github.com:piwik/piwik
Refs #5060 Remove use of substr_compare as it's buggy in 5.5.11 with negative offset
Removing require_once as it's failing on travis ci: https://travis-ci.org/piwik/piwik-ui-tests/builds/24157566
Submodules
Refs #5062 enabling PHP 5.6 tests to see if Piwik is compatible with bleeding edge PHP version
Do not run un-necessary tests on PHP 5.6
Refs #5031 Now getting PHPUnit from composer/packagist. This will make like better for core team devs
Updating readme with instructions.
I also hope this will solve the Autoloader issue on the UI build: https://travis-ci.org/piwik/piwik-ui-tests
Adding PHPUnit to include path, maybe this helps?  refs #5031
Error was https://travis-ci.org/piwik/piwik/jobs/24163923
PHPUnit doc says to add vendor/bin to include path refs #5031