[C++/Python] Raise exception if old metadata encountered

[asfimport]

For the moment, we intend for Arrow users to develop head-to-head, i.e. old metadata will not be supported. This will help prevent issues caused by upgrading one component (e.g. pyarrow) but not another (e.g. the Java JARs)

Reporter: Wes McKinney / @wesm
Assignee: Wes McKinney / @wesm

Related issues:

• Arrow 0.3 release (blocks)

_{Note: This issue was originally created as ARROW-779. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
PR: #507

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 507
#507