systemclock: Use high resolution timer on Windows if possible

Default Windows' system timer has poor resolution (less than about 16ms)
which is not suitable for media processing.
To use high-resolution timer on Windows, we need to make use of timeBeginPeriod() API

NOTE: timeBeginPeriod() will change global system setting, that means
other applications on the system will be affected. If user doesn't
want to change global system setting, "GST_DISABLE_WINMM_CLOCK_TIMER"
environment can be used for the purpose.

NOTE: After the use of updated system clock precision, we will
restore the previous setting by using timeEndPeriod()
36 jobs for !715 with win32-clock in 59 seconds (queued for 5 seconds)
latest detached
Status Job ID Name Coverage
  Build Docker
passed #6024949
alpine amd64 manifest builder docker

00:00:30

passed #6024948
android docker

00:00:16

passed #6024946
cerbero fedora amd64 docker

00:00:16

passed #6024945
fedora amd64 docker

00:00:15

passed #6024951
gst-indent amd64 docker

00:00:11

 
  Preparation
passed #6024956
check allow-edit

00:00:08

passed #6024954
gst indent

00:00:28

manual #6024953
manual
manifest
 
  Build
created #6024973
gstreamer
build cerbero cross-android universal
created #6024981
gst-ios-13.2
build cerbero cross-ios universal
created #6024975
gstreamer
build cerbero cross win32
created #6024977
gstreamer
build cerbero cross win64
created #6024971
gstreamer
build cerbero fedora x86_64
created #6024979
gst-macos-10.15
build cerbero macos x86_64
created #6024983
docker windows gstreamer-windows 1809
build cerbero msvc x86_64
created #6024963
build clang fedora x86_64
created #6024968
docker windows 1809 allowed to fail manual
build msys2
created #6024957
build nodebug fedora x86_64
created #6024959
build static fedora x86_64
created #6024961
build static nodebug fedora x86_64
created #6024964
docker windows 1809
build vs2017 amd64
created #6024966
docker windows 1809
build vs2017 x86
 
  Test
created #6024986
gstreamer
check fedora
created #6024987
gstreamer
integration testsuites fedora 1/4
created #6024990
gstreamer
integration testsuites fedora 2/4
created #6024992
gstreamer
integration testsuites fedora 3/4
created #6024993
gstreamer
integration testsuites fedora 4/4
created #6024998
gstreamer
valgrind bad
created #6024995
gstreamer
valgrind base
created #6024994
gstreamer
valgrind core
created #6024999
gstreamer
valgrind ges
created #6024996
gstreamer
valgrind good
created #6024997
gstreamer
valgrind ugly
 
  Integrate
created #6025000
cross-android universal examples
created #6025002
gst-ios-13.2
cross-ios universal examples
created #6025001
documentation