Augmenting 3-deep report for the purpose of demonstrating the sub-sub-report CustomExpression bug:

Unknown property 'customExpression_for_DJR_1234_COLUMN_0'

(See line 130)
Removing unnecessary recursive call to `compileOrLoadSubreports`. The next line calls into `generateJasperReport`, which itself calls `compileOrLoadSubreports`. The net effect is that now sub-subreports aren't doubly registered and thus now CustomExpressions now work within them.
Applying the same logic to header subreports as footer subreports
Bumping Apache POI library. A new one just came out with 'significant performance improvements and bug fixes'.
Merge remote-tracking branch 'inanutshellus/pullrequests'
Better documentation and login info for subreports