Read packed fields for protobuf compability

Protobuf allows some fields to be encoded packed:

https://developers.google.com/protocol-buffers/docs/encoding#optional

This patch will allow protostuff to read these fields.
Fix curly formatting
Update after code review
Update CodedInput with packed support
googlecode issue 165
Merge pull request #62 from dyu/gcode-issue-165

googlecode issue 165
Remove wildcard import in CodedInput
Simplify readFieldNumber
Merge branch 'master' into mzeo/allow-packed-repeated

Conflicts:
	protostuff-core/src/main/java/io/protostuff/CodedInput.java
Merge pull request #44 from mzeo/allow-packed-fields

Add support for packed fields.