Completely restructured the test for the helper feature. The tests were split into three categories:
* general tests for the helper feature (thlp*)
* tests for class helpers (tchlp*)
* tests for record helpers (trhlp*)

With my current yet-to-be-commited implementation nearly all tests pass, but some fail because of missing FPC features:
* thlp30.pp currently fails because of generic constraints, but should fail despite the constraints
* thlp29.pp fails, because generic methods are not yet supported
* trhlp8.pp, trhlp9.pp, trhlp10.pp fail, because one can't use default properties using the abbreviated syntax
* trhlp17.pp, trhlp18.pp, trhlp19.pp fail, because nested types are not supported for records

git-svn-id: branches/svenbarth/classhelpers@17237 -