Update the protocol buffer compiler plugin to use Int64 from the fixnum package

Update the protocol buffer compiler plugin to use Int64 from the fixnum package

The 64-bit integers in protocol buffer messages now use the Int64
object from the fixnum package for representing 64-bit integers
instead of an 8-byte binary buffer.

When generating JSON the 64-bit integers in the 53-bit range are
written as integers. Larger integeres are still written as strings.

R=sigmund@google.com
BUG=

Committed: https://github.com/dart-lang/protoc-plugin/commit/8f6ddff

[Søren Gjesse, 2013-10-02 14:03:15]

This requires https://chromiumcodereview.appspot.com/25634007/ to land.

[Søren Gjesse, 2013-10-04 06:59:41]

Friendly ping.

[Siggi Cherem (dart-lang), 2013-10-04 18:34:39]

lgtm

https://chromiumcodereview.appspot.com/25708003/diff/1/pubspec.yaml
File pubspec.yaml (right):

https://chromiumcodereview.appspot.com/25708003/diff/1/pubspec.yaml#newcode2
pubspec.yaml:2: version: 0.2.0
FYI 0.1.3 would be fine too. (while we are < version 0, we basically shifted the
meaning semantic versioning of the major/minor/patch numbers:
 0.1.2 => 0.1.3 (breaking change)
 0.1.2 => 0.1.2+1 (non-breaking change)

[Søren Gjesse, 2013-10-07 06:53:24]

Committed patchset #1 manually as r8f6ddff (presubmit successful).