Updated mail config comments from postmark to mailgun

Iron.io config less error prone.

In iron.io settings 'token' is the first field and 'Project ID' is the second. The proposed order makes it less error prone.

5x boost for EU customers

Add required_with_all validation message

added alt to img tag in hello

added required alt tag to img, now successfully passes w3c validation

This option is already supported in 'Illuminate/Queue/Connectors/IronConnector.php'
Having this option hidden works well only for North America. However for EU having it set to EU servers give 5X boost in network performance with iron.io

Improvement of validation traduction for "email" rule

Added required_without_all

Updating .htaccess for consistency

added license badge

tabs to spaces

Add php artisan clear-compiled to post-install-cmd

laravel/framework#3152
Signed-off-by: crynobone <crynobone@gmail.com>

Fixing indentation to be consistent

Corrected the spelling of 'maintenance' in maintenance mode comment block

Enhancements to the 4.0>4.1 upgrade guide.

Re-order upgrade instructions

composer update throws an error while executing artisan if you have not yet done this step:

- Remove call to `redirectIfTrailingSlash` in `bootstrap/start.php` file.

Added new steps - upgrade.md