jackson-databind: Add PackageVersion to improve Android memory usage

This builds on the support in
https://github.com/FasterXML/jackson-core/pull/49 to improve Android
memory usage for apps that use jackson-databind.
Update PackageVersion.java.in to implement Versioned.
Refactor shared properties and plugin logic into oss-parent.

Revert changes to .gitignore, now that generated sources are under target/ dir.
Add a unit test.
Implementing #141
Added test to verify that [JACKSON-882] does not occur with 2.1
Fixing issue #142, problems with EnumMap, polymorphic types
Tests for github issue #138
Walkaround for #138
This should fail. Walkaround should not be part of test case.
Merge pull request #139 from bgertzfield/master

jackson-databind: Add PackageVersion to improve Android memory usage
update parent pom version
Merge pull request #143 from Airborn/master

Test case for Issue #138 @JsonIdentityReference not working with collections
update annotations dep
update parent pom
one more update fore replacer
Yet more work on cleaning up version handling
and remove unnecessary file
MissingNode: fix bug in is{Value,Container,MissingNode}() contract

The Javadoc says that for any given node, only one such method may return true.

For MissingNode however, true was returned for both isMissingNode() and
isValueNode().
Merge pull request #144 from fge/missingnodefix

MissingNode: fix bug in is{Value,Container,MissingNode}() contract