Import YAML-Parser yaml-cpp

Version: tags/yaml-cpp-0.6.2
  License: MIT

yaml-cpp requires c++11 and since yaml-cpp 0.6 there is no dependency on
boost anymore.

A YAML parser is needed for the ClangTools plugin to parse exported
diagnostics from clang-tidy/clazy:

  $ clang-tidy -export-fixes=/tmp/tidy.yaml source.cpp

The imported source is stripped of unneeded files as documented with

  src/libs/3rdparty/yaml-cpp/patches/0001-yaml-cpp-Strip-unneeded-sources.patch
  (generated with "git format-patch -D")

Change-Id: Ib0a521b5aff4b1cd058eb480bfb99fde4b320dc7
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

cmake/QtCreatorAPI.cmake

@@ -324,7 +324,7 @@ function(add_qtc_library name)
   add_library(${IDE_CASED_ID}::${name} ALIAS ${name})
   set_public_headers(${name} "${_arg_SOURCES}")
 
-  if (${name} MATCHES "^[^0-9]+")
+  if (${name} MATCHES "^[^0-9-]+$")
     string(TOUPPER "${name}_LIBRARY" EXPORT_SYMBOL)
   endif()