BF: Fix AttributeError if click in Builder output

If trace lines in Builder's output dialog were clicked and Coder was
not open then an Attribute Error was raised. This was fixed by opening
Coder with showCoder() before Builder changing it by using gotoLine().
DOC: Fix typo
BF: Fix help strings
Merge pull request #466 from philippwiesemann/fix-builder-goto-error

BF: Fix AttributeError if click in Builder output