[git] git ignore exception

The solution depends on the relation between the git ignore rule and the exception rule:

  1. Files/Files at the same level: use the @Skilldrick solution.
  2. Folders/Subfolders: use the @Matiss Jurgelis solution.
  3. Files/Files in different levels or Files/Subfolders: you can do this:

    *.suo
    *.user
    *.userosscache
    *.sln.docstates
    
    # ...
    
    # Exceptions for entire subfolders
    !SetupFiles/elasticsearch-5.0.0/**/*
    !SetupFiles/filebeat-5.0.0-windows-x86_64/**/*
    
    # Exceptions for files in different levels
    !SetupFiles/kibana-5.0.0-windows-x86/**/*.suo
    !SetupFiles/logstash-5.0.0/**/*.suo