Removed redundant m_strVersion = "2.0" statements.

It is already set in the base class OTContract.
Merge pull request #408 from benma/cleanup

Removed redundant m_strVersion = "2.0" statements.
OTContract: rename class to Contract
OTContract: rename files to Contract.{h,c}pp
Merge pull request #409 from toxeus/renameOTContract

OTContract: rename to Contract