Tests: PHP-Code-Sniffer for WordPress coding standards

The plugin will be read by many WP developers.
Every developer has his own style but WordPress has a standard.
To fulfill the WP coding standard the code is testable against that.

- WordPress-VIP coding standards are used
Tests: WordPress Test-Libs will be stored in project

The test-libs of WordPress were stored in /tmp folder.
The test-libs are unreachable for the IDE
and are deleted after every restart.
Putting the test-libs in a local folder makes them permanent rechable.

- /vendor/wordpress-tests-lib will contain PHPUnit bootstrap for WordPress
Tests: Suite admin added

Tests did run in only one global suite.
One suite can not cover the test depending on `is_admin()`.
The admin-Suite has been added to cover `is_admin()` dependencies.

- /tests/bootstrap-admin.php sets WP_ADMIN
  and tries to set $_SERVER['PHP_SELF'] correctly
- /.travis.yml covers admin tests
- /phpunit.xml global suite will exclude admin tests
  and admin-suite has its own directory
Docs: Enhanced composer file with all possible information

- Project name, description, version, license and type
- Keywords, homepage, authors and support channels
- Config to place things in a more linux directory structure
Docs: Pride of stability and testing shown in readme
Docs: Wiki added to directly change documentation
Tests: Travis does not clone sub-modules
Docs: PHPDoc used to check for missing docs

- install-date.php documentation enhanced
- /bin/parse-api-doc.sh checks for missing docs
Tests: Script that runs all tests
Tests: Pre-test if PHP-Syntax is valid

Some tests abort when the syntax is incorrect.
Checking them before the test will list the bad files.
QA: Squizlabs CodeSniffer upgraded to version 1.5

Using the latest version will provide better code quality.
QA: PHP Mess Detector upgraded to version 2.1

Using the latest version will provide better code quality.
Tests: Code coverage for tests

Some bugs hide in untested corners of the code.
Code coverage will show how much of the code has been tested.
Tests: UnitTests must pass before every push
Tests: Composer itself and the JSON will be tested for integrity
Tests: WordPress is reachable via browser
Tests: Composer updates itself before each test
Tests: Browser-Tests are made with Behat, Mink and Selenium