[style] detab runnable/template4.d
fix Issue 12725 - IFTI should consider instantiated types with dependent template parameters
more selective editorconfig

- only apply config to C and D source files
fix Issue 7469 - template mangling depends on instantiation order
Merge pull request #3536 from 9rnsr/fix7469

Issue 7469 - template mangling depends on instantiation order
Merge pull request #3538 from MartinNowak/editorconfig

more selective editorconfig