While we might never be able to have 100% of our code strict, we can at
the very least do it for all of our tests. This ensures that our tests
are using our API with the types as intended by the test author, and not
silently be cast to what our API requires.
* Read Code Page for Xls ListWorksheetInfo/Names for BIFF5
Fix#3671. Xls reader was not processing Code Page as part of functions ListWorksheetInfo/Names, which was causing them to fail for for BIFF5 (and BIFF7); this was not a problem for BIFF8. There were no unit tests for these functions for either BIFF5 or BIFF8. There are now.
* Add getVersion and getCodePage Methods
These came about because test file for non-standard codepage was supposed to be BIFF5, but turned out to be BIFF8 using UTF-16 with some string data otherwise encoded. Add a BIFF5 equivalent (some hex editing was required), and the means to distinguish one from the other.
* Found MACCENTRALEUROPE Text in BIFF8
It was used for 'Last Modified By' property, even though bulk of spreadsheet uses UTF-16LE. Add a test.