Add a build profile for Hadoop 2. The default profile uses Hadoop 1.

* Enforce common versions of dependencies by using Maven properties.
* Use Hadoop version 1.0.1 since that is the first release to include
hadoop-client.
* Create JARs with and without a hadoop1/hadoop2 classifier. By building
first for Hadoop 2, then for Hadoop 1, then deploying, there are three
JARs: two for Hadoop 1 (hadoop1 classifier, no classifier) and one for
Hadoop 2 (hadoop2 classifier).
* Hadoop 1.1.0 changed the Reporter API to add an abstract getProgress()
method. Avoid this incompatibility by excluding
DeprecatedContainerInputFormat and the cascading and scrooge modules
from the Hadoop 2 build for the time being.