oxNew autocompletion in PhpStorm

Now IDE helper generates helper file .phpstorm.meta.php/oxid.meta.php for PhpStorm IDE, which adds autocompletion for created objects via oxNew.

Add deprecated tag to PHPDoc block of BC classes

Enhancement: Some class aliases are build for backwards compstible reasons only. These classes are deprecated and should not be used and more.
A PHPDoc block with a deprecation tag was added to these classes in order to assist the IDE on code inspections.

Check if config.inc.php file exists

Ide Helper check that the configuration file - config.inc.php - exists.
This was done because:
Composer calls Ide Helper for OXID eShop on install/update to generate helper file for a project.
IDE helper relies that some OXID eShop configuration already exist in file config.inc.php
Calling it without this file creates an error which stops composer install process.

Make IDE helper work without a database connection

Some not existent classes trigger a database connection request via ModuleAutoload.
ModuleAuto wil not be able to resolve this classes anyway and in order to make the IDE helper more flexible, ModuleAutoload is unregistered.
Additionally all exceptions will be caught and printed to sdtout.

Fix location of BackwardsCompatibilityClassMap

Depending on the way the sources of the OXID eShop are checked out, the "Core/Autoload" directory may be in one place or another.
There was a constant introduced in bootstrap.php to address this problem and this constant is use now in the generator as well.

Filter warning for expected not existing classes

In OXID eShop Community Edition there are some backwards compatible classes expected to be missing, as they belong to OXID eShop Professional Edition or OXID eShop Enterprise Edition.
These expected missing classes are now filtered from the "Class Foo does not exist" warnings.

Adapt IDE helper to new autoloading mechanism

This is a new major version as the autoloading mechanism has changed and the files, which are taken to generate the IDE helper file are at a different place now.
Also the old ox* classes have been removed and only a mapping file was left, so these ox* classes were included into the IDE helper file.

Caveat:
The recommended way to use the global factory function oxNew is using the ::class notation and the virtual namespace:
$article = oxNew(\OxidEsales\Eshop\Application\Model\Article::class);
Autocompletion of methods on the $article variable does not work using this notation.

Initial release

v1.0.0

Update documentation as product name was changed