Add option to suppress validation of sheet titles
Based on a "lowest common denominator" approach to compatibility,
we will continue to enforce a 31-character limit for sheet titles.
However, this limit should not be enforced when loading an existing
file.
Added a new optional parameter to Worksheet::setTitle() and
Worksheet::setCodeName() to suppress validation and massaging,
based on the premise that existing files should be given a
best-effort approach to loading and parsing. Unfortunately, it's
not possible with the current architecture to prevent users from
making use of this functionality, aside from with a strongly-worded
warning.
Added test coverage. I didn't see any existing unit tests of the
Worksheet class, so I created a new test to cover these methods.
Fixes#176
Mikkel Paulson