add pybind11 port

ports/pybind11/CONTROL

@@ -0,0 +1,3 @@
+Source: pybind11
+Version: 2.0.1
+Description: pybind11 is a lightweight header-only library that exposes C++ types in Python and vice versa, mainly to create Python bindings of existing C++ code.

ports/pybind11/portfile.cmake

@@ -0,0 +1,45 @@
+include(vcpkg_common_functions)
+
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/pybind11-2.0.1)
+
+vcpkg_download_distfile(ARCHIVE
+    URLS "https://github.com/pybind/pybind11/archive/v2.0.1.tar.gz"
+    FILENAME "pybind11-2.0.1.tar.gz"
+    SHA512 c156d01321b79eaac7992f431b30a9f4fb06e92909bf02e76a45e2d9329e7949dad686ee42a49c293214aec2a79eb400fa3373d2ba4876271895822096b50ff4
+)
+vcpkg_extract_source_archive(${ARCHIVE})
+
+# link the MSVC runtime statically if set.
+if(VCPKG_CRT_LINKAGE STREQUAL dynamic)
+    set(CRUNTIME /MD)
+else()
+    set(CRUNTIME /MT)
+endif()
+
+#STREQUAL empty here means the enviroment variable is not defined.
+if(NOT $ENV{PYTHON} STREQUAL "")
+    set(PYTHON_VER $ENV{PYTHON})
+else()
+    message(FATAL_ERROR "You must set the PYTHON environment variable, eg. set PYTHON=3.5 or export PYTHON=3.5")
+endif()
+
+if(NOT $ENV{CPP} STREQUAL "")
+    set(CPP_STD $ENV{CPP})
+else()
+    message(FATAL_ERROR "You must set the CPP environment variable, eg. set CPP=11 or export CPP=11.")
+endif()
+message(STATUS "Using C++${CPP_STD} and Python ${PYTHON_VER}")
+vcpkg_configure_cmake(
+        SOURCE_PATH ${SOURCE_PATH}
+        OPTIONS
+            -DPYBIND11_PYTHON_VERSION=${PYTHON_VER}
+            -DPYBIND11_CPP_STANDARD=${CPP_STD}
+)
+
+vcpkg_install_cmake()
+
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/)
+
+
+# copy license
+file(INSTALL ${SOURCE_PATH}/LICENSE DESTINATION ${CURRENT_PACKAGES_DIR}/share/pybind11/copyright)