poppler: cairo: Don't override the antialias settings from the cairo_t

This partially reverts commit 853e9499, which made CairoOutputDev store
the antialias setting, and applying it to its cairo context.

Instead, just copy the antialias (and font antialias) setting from the
passed cairo context to newly created contexts.  That way, the application
can control the antialias settings.

Use this in pdftocairo to implement its -antialias option.

https://bugs.freedesktop.org/show_bug.cgi?id=94977
poppler/poppler!89
Status Job ID Name Coverage
  Build
passed #1277970
build

00:02:32

passed #1277975
build_android

00:01:52

passed #1277971
build_clang_libcpp

00:03:16

passed #1277974
build_clazy

00:02:52

passed #1277973
build_mingw64_fedora

00:02:20

passed #1277972
build_ubuntu_16_04

00:01:24