Remove YCM config

Not clear if it even works anymore.
We suggest maintaining your own YCM config or using a language server
like CCLS in combination with the generated compile_commands.json

.ycm_extra_conf.py

@@ -1,126 +0,0 @@
-import os
-import ycm_core
-
-# Default flags
-flags = [
-    '-std=c++14',
-    '-Wall',
-    '-Wextra',
-
-    # Relative paths are corrected by MakeRelativePathsInFlagsAbsolute
-    '-Isrc',
-    '-Iinclude',
-    '-Ilib/concurrentqueue/include',
-    '-Ilib/i3ipcpp/include',
-    '-Ilib/xpp/include',
-    '-Itests',
-
-    '-I/usr/include',
-    '-I/usr/include/freetype2',
-    ]
-
-# Base directory of the project, parent directory of all source files
-project_dir = os.path.dirname(os.path.abspath(__file__))
-
-# This assumes that everyone coding for this project builds inside the 'build'
-# directory
-compilation_database_folder = project_dir + "/build"
-
-if os.path.exists(compilation_database_folder):
-  database = ycm_core.CompilationDatabase(compilation_database_folder)
-else:
-  database = None
-
-SOURCE_EXTENSIONS = ['.cpp', '.cxx', '.cc', '.c', '.m', '.mm']
-
-# Converts all relative paths in the given flag list to absolute paths with
-# working_directory as the base directory
-def MakeRelativePathsInFlagsAbsolute(flags, working_directory):
-  if not working_directory:
-    return list(flags)
-  new_flags = []
-  make_next_absolute = False
-  path_flags = ['-isystem', '-I', '-iquote', '--sysroot=']
-  for flag in flags:
-    new_flag = flag
-
-    if make_next_absolute:
-      make_next_absolute = False
-      if not flag.startswith('/'):
-        new_flag = os.path.join(working_directory, flag)
-
-    for path_flag in path_flags:
-      if flag == path_flag:
-        make_next_absolute = True
-        break
-
-      if flag.startswith(path_flag):
-        path = flag[len(path_flag):]
-        new_flag = path_flag + os.path.join(working_directory, path)
-        break
-
-    if new_flag:
-      new_flags.append(new_flag)
-  return new_flags
-
-def IsHeaderFile(filename):
-  extension = os.path.splitext(filename)[1]
-  return extension in ['.h', '.hxx', '.hpp', '.hh', ".inl"]
-
-# Tries to query the compilation database for flags
-# For header files it tries to use the flags for a corresponding source file
-def GetCompilationInfoForFile(filename):
-  if not database:
-    return None
-
-  # The compilation_commands.json file generated by CMake does not have entries
-  # for header files. We try to use the compile flags used for the corresponding
-  # source file.
-  #
-  # For this try to replace the file extension with an extension that
-  # corresponds to a source and we also try to replace the 'include' folder in
-  # the path with 'src'
-  if IsHeaderFile(filename) :
-    basename = os.path.splitext(filename)[0]
-
-    # Absolute path of the include and source directories
-    include_dir = project_dir + "/include"
-    src_dir = project_dir + "/src"
-
-    # Absolute path without file extension, with the 'include' folder replaced
-    # with 'src' in the path
-    src_basename = None
-    # If the header file is inside the include dir, try to search in the src dir
-    if basename.startswith(include_dir):
-      # file path relative to include dir
-      rel_path_include = os.path.relpath(basename, include_dir)
-      src_basename = os.path.join(src_dir, rel_path_include)
-
-    for extension in SOURCE_EXTENSIONS:
-      # A list of all possible replacement files to be searched
-      replacement_files = [basename + extension]
-
-      if src_basename:
-        replacement_files.append(src_basename + extension)
-
-      for replacement_file in replacement_files:
-        if os.path.exists(replacement_file):
-          comp_info = database.GetCompilationInfoForFile(replacement_file)
-          if comp_info.compiler_flags_:
-            return comp_info
-  return database.GetCompilationInfoForFile(filename)
-
-def FlagsForFile(filename, **kwargs):
-  compilation_info = GetCompilationInfoForFile(filename)
-  if compilation_info and compilation_info.compiler_flags_:
-    # Bear in mind that compilation_info.compiler_flags_ does NOT return a
-    # python list, but a "list-like" StringVec object
-    final_flags = MakeRelativePathsInFlagsAbsolute(
-        [x for x in compilation_info.compiler_flags_ if x != "-Werror"],
-        compilation_info.compiler_working_dir_)
-  else:
-    # We use default flags if GetCompilationInfoForFile can't find any flags
-    relative_to = project_dir
-    final_flags = MakeRelativePathsInFlagsAbsolute(flags, relative_to)
-
-  return {'flags': final_flags, 'do_cache': True}