Implement type-of ideslave command, which uses Check in the background

Furthermore, instead of printing with iputStrLn, use iPrintResult to
indicate that the command finished successfully
Implement CaseSplit in IdeSlave
support for add-clause in IdeSlave
support for add-missing, make-with-block and proofsearch for ideslave
support for add-proof-clause in IdeSlave
Re-insert the missing newlines in :t for metavars
Merge pull request #626 from david-christiansen/hannes-ide

Fix minor :t display issue from our IDESlave work last night