Fix url's in installer.
Set single language as default.
Add an object containg all installation data.
Consistent indentation.
Refactor first installer step to use an object.
Make the modules step work with an object.
Set database information from object.
Make login step work with object.
Make the installer work with the data object.
Refactor boolean getters to has-style methods.
Add PHPDoc.
Merge pull request #905 from forkcms/installer-with-entity

Installer with entity
Avoid using method return value in write context.
Fix missing use statement.
Add missing use statement.

Also: fix wrong indentation.
Fix file permissions.
Fix PHPDocs and typehints.
Remove unused use statements.
Fix Compile error.
Bump version number for upcoming release.