Allow setting the pickler to use in pyarrow serialization.

[asfimport]

We currently try to import cloudpickle and failing that fall back to pickle. However, given that there are many versions of cloudpickle and they are typically incompatible with one another, the caller may want to specify a specific version, so we should allow them to set the specific pickler to use.

Reporter: Robert Nishihara / @robertnishihara
Assignee: Robert Nishihara / @robertnishihara

PRs and other links:

• GitHub Pull Request #1493

_{Note: This issue was originally created as ARROW-2011. Please see the migration documentation for further details.}

[asfimport]

Philipp Moritz / @pcmoritz:
Issue resolved by pull request 1493
#1493