[oniguruma] Add new port (microsoft#5432)

* [oniguruma] Add new port

* [oniguruma] Fix ONIG_EXTERN

* [oniguruma] Disable vcpkg_test_cmake (failed on x64-windows)

* [oniguruma] Update to 2019-02-26 to fix UWP sdl compile error

ports/oniguruma/CONTROL

@@ -0,0 +1,6 @@
+Source: oniguruma
+Version: 2019-02-26
+Description: Modern and flexible regular expressions library
+
+Feature: non-posix
+Description: Disable POSIX API

ports/oniguruma/portfile.cmake

@@ -0,0 +1,50 @@
+include(vcpkg_common_functions)
+
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO kkos/oniguruma
+    REF 502b1f416746ed8700498229bbfceb180e400fbc
+    SHA512 0faf12f415de59716d8faa4d3dc026874c3bd6a3624f75f2a184843025294eb885d57164ae6dcb916cba5c7d1a4da4bcb0dc23fce3ceae5b34b7320e8f0e2c02
+    HEAD_REF master
+)
+
+if("non-posix" IN_LIST FEATURES)
+    set(ENABLE_POSIX_API OFF)
+else()
+    set(ENABLE_POSIX_API ON)
+endif()
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    PREFER_NINJA
+    OPTIONS
+        -DENABLE_POSIX_API=${ENABLE_POSIX_API}
+)
+
+vcpkg_install_cmake()
+
+vcpkg_fixup_cmake_targets(CONFIG_PATH lib/cmake/${PORT})
+
+file(REMOVE_RECURSE
+    ${CURRENT_PACKAGES_DIR}/debug/include
+    ${CURRENT_PACKAGES_DIR}/debug/share
+)
+
+if(VCPKG_LIBRARY_LINKAGE STREQUAL dynamic)
+    vcpkg_replace_string(${CURRENT_PACKAGES_DIR}/include/oniguruma.h
+        "#if defined(ONIGURUMA_EXPORT)"
+        "#if 0 // defined(ONIGURUMA_EXPORT)"
+    )
+else()
+    # oniguruma.h uses `\n` as line break.
+    vcpkg_replace_string(${CURRENT_PACKAGES_DIR}/include/oniguruma.h
+        "#ifndef ONIG_EXTERN\n#if defined(_WIN32) && !defined(__GNUC__)"
+        "#if 0\n#if defined(_WIN32) && !defined(__GNUC__)"
+    )
+endif()
+
+# Handle copyright
+configure_file(${SOURCE_PATH}/COPYING ${CURRENT_PACKAGES_DIR}/share/${PORT}/copyright COPYONLY)
+
+# CMake integration test
+#vcpkg_test_cmake(PACKAGE_NAME ${PORT})