TYPO3 CMS v8 Support

- Support for TYPO3 7.6 - 8.5.0-dev
- composer.json improvements
- fixed exception (Please review them exactly - it's the first time I'm working with TYPO3 backend modules)
- removed obsolete TER-v1 ext_emconf.php options

I look forward to get some feedback ¯\_(ツ)_/¯

See merge request !10

* add Illustrator source file in private folder
* add new extension svg icon in new file location
* activate new svg icon for the be module link
* some CGL in ext_tables.php

¯\_(ツ)_/¯

Use `\TYPO3\CMS\Core\Page\PageRenderer::addJsInlineCode`
for adding inline javascript code

* raise minimum TYPO3 version
* raise upper PHP version limit

[BUGFIX] Make FileService PHP7 compatible



See merge request !9

[BUGFIX] Make ExtendedIfViewHelper PHP7 compatible



See merge request !8

[BUGFIX] Do not use deprecated third parameter of addTCAcolumns()



See merge request !7

Resolves: forge.typo3.org/issues/68523

The problem was when the session is empty, until user makes some selection. In case of empty session (selection not in session), first item of numSiteConstsOptions is selected and saved to session.
Method 'assignViewWidthMenuVariables' does that and sends selection and options to view.