Update Doxygen config for the latest version.

docs/Doxyfile

@@ -7,7 +7,6 @@ OUTPUT_DIRECTORY       = docs/doxygen
 CREATE_SUBDIRS         = NO
 ALLOW_UNICODE_NAMES    = NO
 OUTPUT_LANGUAGE        = English
-OUTPUT_TEXT_DIRECTION  = None
 BRIEF_MEMBER_DESC      = YES
 REPEAT_BRIEF           = YES
 ABBREVIATE_BRIEF       =
@@ -64,6 +63,7 @@ INTERNAL_DOCS          = NO
 CASE_SENSE_NAMES       = NO
 HIDE_SCOPE_NAMES       = NO
 HIDE_COMPOUND_REFERENCE= NO
+SHOW_HEADERFILE        = YES
 SHOW_INCLUDE_FILES     = YES
 SHOW_GROUPED_MEMB_INC  = NO
 FORCE_LOCAL_INCLUDES   = NO
@@ -90,6 +90,7 @@ QUIET                  = NO
 WARNINGS               = NO
 WARN_IF_UNDOCUMENTED   = NO
 WARN_IF_DOC_ERROR      = YES
+WARN_IF_INCOMPLETE_DOC = YES
 WARN_NO_PARAMDOC       = NO
 WARN_AS_ERROR          = NO
 WARN_FORMAT            = "$file:$line: $text"
@@ -123,10 +124,6 @@ REFERENCES_LINK_SOURCE = YES
 SOURCE_TOOLTIPS        = YES
 USE_HTAGS              = NO
 VERBATIM_HEADERS       = YES
-CLANG_ASSISTED_PARSING = NO
-CLANG_ADD_INC_PATHS    = YES
-CLANG_OPTIONS          =
-CLANG_DATABASE_PATH    =
 ALPHABETICAL_INDEX     = YES
 IGNORE_PREFIX          =
 GENERATE_HTML          = YES
@@ -146,6 +143,7 @@ HTML_DYNAMIC_SECTIONS  = NO
 HTML_INDEX_NUM_ENTRIES = 100
 GENERATE_DOCSET        = NO
 DOCSET_FEEDNAME        = "Doxygen generated documentation"
+DOCSET_FEEDURL         =
 DOCSET_BUNDLE_ID       = org.doxygen.Project
 DOCSET_PUBLISHER_ID    = org.doxygen.Publisher
 DOCSET_PUBLISHER_NAME  = Publisher
@@ -168,14 +166,17 @@ GENERATE_ECLIPSEHELP   = NO
 ECLIPSE_DOC_ID         = org.doxygen.Project
 DISABLE_INDEX          = NO
 GENERATE_TREEVIEW      = NO
+FULL_SIDEBAR           = NO
 ENUM_VALUES_PER_LINE   = 4
 TREEVIEW_WIDTH         = 250
 EXT_LINKS_IN_WINDOW    = NO
+OBFUSCATE_EMAILS       = YES
 HTML_FORMULA_FORMAT    = png
 FORMULA_FONTSIZE       = 10
 FORMULA_TRANSPARENT    = YES
 FORMULA_MACROFILE      =
 USE_MATHJAX            = NO
+MATHJAX_VERSION        = MathJax_2
 MATHJAX_FORMAT         = HTML-CSS
 MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
 MATHJAX_EXTENSIONS     =
@@ -203,7 +204,6 @@ PDF_HYPERLINKS         = YES
 USE_PDFLATEX           = YES
 LATEX_BATCHMODE        = NO
 LATEX_HIDE_INDICES     = NO
-LATEX_SOURCE_CODE      = NO
 LATEX_BIB_STYLE        = plain
 LATEX_TIMESTAMP        = NO
 LATEX_EMOJI_DIRECTORY  =
@@ -213,7 +213,6 @@ COMPACT_RTF            = NO
 RTF_HYPERLINKS         = NO
 RTF_STYLESHEET_FILE    =
 RTF_EXTENSIONS_FILE    =
-RTF_SOURCE_CODE        = NO
 GENERATE_MAN           = NO
 MAN_OUTPUT             = man
 MAN_EXTENSION          = .3
@@ -225,7 +224,6 @@ XML_PROGRAMLISTING     = YES
 XML_NS_MEMB_FILE_SCOPE = NO
 GENERATE_DOCBOOK       = NO
 DOCBOOK_OUTPUT         = docbook
-DOCBOOK_PROGRAMLISTING = NO
 GENERATE_AUTOGEN_DEF   = NO
 GENERATE_PERLMOD       = NO
 PERLMOD_LATEX          = NO
@@ -247,7 +245,6 @@ GENERATE_TAGFILE       =
 ALLEXTERNALS           = NO
 EXTERNAL_GROUPS        = YES
 EXTERNAL_PAGES         = YES
-CLASS_DIAGRAMS         = YES
 DIA_PATH               =
 HIDE_UNDOC_RELATIONS   = YES
 HAVE_DOT               = NO
@@ -269,6 +266,7 @@ CALL_GRAPH             = NO
 CALLER_GRAPH           = NO
 GRAPHICAL_HIERARCHY    = YES
 DIRECTORY_GRAPH        = YES
+DIR_GRAPH_MAX_DEPTH    = 1
 DOT_IMAGE_FORMAT       = png
 INTERACTIVE_SVG        = NO
 DOT_PATH               =