Fix NPE for command with no arguments

[jes: fixed whitespace and commit message]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Remove addressed TODO

[jes: split out into separate commit]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add setType() method

[jes: split out into separate commit]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add test for commands during nar-process-libraries

[jes: fixed commit message]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Update nar-process-libraries command test for Windows

[jes: since Windows does not have an 'echo' executable, we simply add
an 'echo.bat' file instead of introducing a new command name.]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'fix-npes'

This merges a cleaned-up version of Steve Soloski's PR #98.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>