Edited Feature: Write stress tests [109]

Relatively long-running tests for handling large amounts of data, numerous iterations, etc. May have some NUnit, but probably less pervasive than the smaller unit tests.

Couple that with getting runtime performance figures. Think knitr and R Markdown, perhaps.

* Impact of using the lock mechanism on preserve/unpreserve. Guidelines
* Character vectors: measure, and advise best practices.
* Figures on Linux and Mono