Update for Dart 2.x constants

[dnfield]

Dart 2.x has removed support for some deprecated constants (Endianness and UTF8 in particular) that are used by this package.

This change will allow people to use latest/cutting edge releases of Dart, but removes support for 1.x

Users of Dart 1.x would have to use the previous version of this patch, and will not benefit from continued updates.

Fixes #4836 (more discussion there as well)

[aardappel]

Thanks!

[6643]

[1.9.1] Import failed

$ cat pubspec.yaml 
name: zhubao.bin

dependencies:
  flat_buffers: ^1.9.1


$ pub upgrade
Resolving dependencies... (3.3s)
Because zhubao.bin depends on flat_buffers ^1.9.1 which doesn't match any versions, version solving failed.

[dnfield]

@aardappel it still needs to be published on pub - there's a script in the package to assist with that https://github.com/google/flatbuffers/blob/master/dart/publish.sh

@6643 in the meantime you can add a reference directly to Git, with something like this:

dependencies:
  flat_buffers:
    git:
      url: git://github.com/google/flatbuffers.git
      path: dart

[dnfield]

@6643 I should add I haven't tested that but the documentation says it should work... If it doesn't, you can just pull it down locally somewhere and set it up as a local package.

[aardappel]

published: https://pub.dartlang.org/packages/flat_buffers

[6643]

@dnfield @aardappel thanks