Remove code which expects new to return null.

new throws an exception on failure instead.
Merge pull request #73 from ahmedcharles/exceptions

Remove code which expects new to return null.
Fix bug with the revert of keyboard nav.
Merge pull request #84 from ahmedcharles/fix

Fix bug with the revert of keyboard nav.
Remove unnecessary include of QDebug.
Merge pull request #85 from ahmedcharles/fix

Add additional include guards that were missed.
Reindent ctelnet.h to use 4 spaces.

This makes it consistent with everything else.
Some more intentionally low controversial formatting.