include-what-you-use: updated to 0.11

IWYU 0.11
[iwyu] Improved recognition of template and specialization uses
[iwyu] Improved CMake build system, see docs for build instructions
[mappings] Improved mappings for Boost, Intel intrinsics and libstdc++
[iwyu_tool] Several bug fixes and improvements
[iwyu_tool] Add --basedir argument to interpret IWYU output from another source tree
[fix_includes] Handle namespaces better
[fix_includes] Add --only_re switch to filter affected files
[fix_includes] Add --reorder/--noreorder switch to toggle reordering of includes

(adam)