prepare for new release: 2021-04-15 (microsoft#61)

The following PRs are included:

* hopefully fix crash in constraints (microsoft#60)
* [vcpkg] allow --version to check the version (microsoft#50)
* Remove baseline warning (microsoft#27)
* [git] always pass autocrlf=false (microsoft#58)
* ignore QtCreator CMake project files (microsoft#54)
* ignore .DS_store files (microsoft#53)
* [vcpkg] x-add-version now also checks if the manifest file is properly formatted (microsoft#43)
* hopefully fix ci issue #16773 (microsoft#34)
* Add docs to set VCPKG_ROOT to run tests (microsoft#45)
* [vcpkg] x-add-version improve speed by calling get_builtin_baseline only once (microsoft#44)
* add clang-format version to format-cxxcode (microsoft#41)
* [vcpkg] Introduce experimental workaround X_VCPKG_NUGET_ID_PREFIX (microsoft#40)
* [supports] Add `native` identifier expression and x-check-support command (microsoft#29)
* [metrics] Split reporting of installs into name:triplet (microsoft#39)
* [vcpkg] Improve error when accessing missing feature (microsoft#38)
* [vcpkg] Allow shallow git registries (microsoft#37)
* Disable git autocrlf when archiving tree (microsoft#36)
* Use only named packages from extra registries (microsoft#35)
* [registries] add metrics (microsoft#30)
* Add vcpkg policy cmake helper port support (microsoft#17)
* [osx] add support for rosetta (microsoft#23)
* don't build tls12-download unless it's needed (microsoft#33)
* Add new telemetry points for versioning (microsoft#21)
* add cmake_minimum_required to vcpkg_tags (microsoft#25)
* [x-add-versions] Perform atomic replacement of versioning files (microsoft#28)
* [tools] support gsutil (microsoft#19)
* add CUDA 11.1 and 11.2 to KEEP_ENV_VARS defaults (microsoft#26)
* Add finite timeout on CURL metrics endpoint. (microsoft#22)
* fix UB in make_error_code(utf8_errc) (microsoft#18)

CMakeLists.txt

@@ -87,7 +87,7 @@ if(NOT DEFINED VCPKG_VERSION OR VCPKG_VERSION STREQUAL "")
     set(VCPKG_VERSION "unknownhash")
 endif()
 
-set(VCPKG_BASE_VERSION "2021-01-13")
+set(VCPKG_BASE_VERSION "2021-04-15")
 
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)