change to LOG.debug until message is not clear and discovered issue is not fixed (but easily reproducible)

* ask to manage ignores only if potentially ignored files are present in project
* VcsIgnoreFilesChecker now check and propose to generate ignore file in project root

* ChangeListManager.isIgnoredFile now check if file contains in ignored files holder
* move isPotentiallyIgnoredFile to util

Language grammar files for generating parser and lexer are mostly taken from .ignore plugin. It was used to generate PSI elements definitions for ignore language.

This fixes GradleDistributionsTest#'distribution via unqualified property reference'.

Vitaly Provodin

This reverts commit b9efff2a
This change caused incorrect propagation of LanguageLevel for nested modules

When view file system tree using `com.intellij.openapi.fileChooser.ex.FileSystemTreeImpl` earlier folder icon was applied only for directories under local file system.