Improve CMake build and install

Author: Isaac Hier

.clang-format

@@ -0,0 +1,2 @@
+BasedOnStyle: Google
+IndentWidth: 4

.clang-tidy

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+---
+Checks:          'clang-diagnostic-*,clang-analyzer-*'
+WarningsAsErrors: ''
+HeaderFilterRegex: ''
+AnalyzeTemporaryDtors: false
+FormatStyle:     none
+User:            isaachier
+CheckOptions:    
+  - key:             google-readability-braces-around-statements.ShortStatementLines
+    value:           '1'
+  - key:             google-readability-function-size.StatementThreshold
+    value:           '800'
+  - key:             google-readability-namespace-comments.ShortNamespaceLines
+    value:           '10'
+  - key:             google-readability-namespace-comments.SpacesBeforeComments
+    value:           '2'
+  - key:             modernize-loop-convert.MaxCopySize
+    value:           '16'
+  - key:             modernize-loop-convert.MinConfidence
+    value:           reasonable
+  - key:             modernize-loop-convert.NamingStyle
+    value:           CamelCase
+  - key:             modernize-pass-by-value.IncludeStyle
+    value:           llvm
+  - key:             modernize-replace-auto-ptr.IncludeStyle
+    value:           llvm
+  - key:             modernize-use-nullptr.NullMacros
+    value:           'NULL'
+...
+

.ycm_extra_conf.py

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+# Copyright (c) 2018, Uber Technologies, Inc
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import os
+import ycm_core
+
+
+def DirectoryOfThisScript():
+  return os.path.dirname( os.path.abspath( __file__ ) )
+
+
+project_dir = DirectoryOfThisScript()
+
+flags = [
+'-Wall',
+'-Werror',
+'-pedantic',
+'-std=c11',
+'-pthread',
+'-x',
+'c',
+'-isystem',
+'/usr/local/include',
+'-I',
+os.path.join(project_dir, 'src/h3lib/include'),
+'-I',
+os.path.join(project_dir, 'src/apps/applib/include')
+]
+
+compilation_database_folder = os.path.join(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' ]
+
+
+def IsHeaderFile( filename ):
+  extension = os.path.splitext( filename )[ 1 ]
+  return extension in [ '.h', '.hxx', '.hpp', '.hh' ]
+
+
+def GetCompilationInfoForFile( filename ):
+  # The compilation_commands.json file generated by CMake does not have entries
+  # for header files. So we do our best by asking the db for flags for a
+  # corresponding source file, if any. If one exists, the flags for that file
+  # should be good enough.
+  if IsHeaderFile( filename ):
+    basename = os.path.splitext( filename )[ 0 ]
+    for extension in SOURCE_EXTENSIONS:
+      replacement_file = basename + extension
+      if os.path.exists( replacement_file ):
+        compilation_info = database.GetCompilationInfoForFile(
+          replacement_file )
+        if compilation_info.compiler_flags_:
+          return compilation_info
+    return None
+  return database.GetCompilationInfoForFile( filename )
+
+
+def FlagsForFile( filename, **kwargs ):
+  if not database:
+    return {
+      'flags': flags,
+      'include_paths_relative_to_dir': DirectoryOfThisScript()
+    }
+
+  compilation_info = GetCompilationInfoForFile( filename )
+  if not compilation_info:
+    return None
+
+  # Bear in mind that compilation_info.compiler_flags_ does NOT return a
+  # python list, but a "list-like" StringVec object.
+  final_flags = list( compilation_info.compiler_flags_ )
+
+  return {
+    'flags': final_flags,
+    'include_paths_relative_to_dir': compilation_info.compiler_working_dir_
+  }