Tests for comments

Delimited comments (<# ... #>) are not implemented yet, so the tests are
marked Explicit or are commented out.
Merge pull request #124 from ygra/CommentTests

Tests for comments
Allow single-character parameter prefixes.
Add "PID" alias for Get-Process -Id.
Added myself to authors.
Merge pull request #128 from Ventero/getprocessalias

Add "PID" alias for Get-Process -Id.
Merge pull request #127 from Ventero/singlecharacter

 Allow single-character parameter prefixes.
Implement console program determining through Windows API.
Proper constant handling.
Add tests, documentation, consistent implementation of process blocking.
Add license notice.
Remove redundant comments and make code more obvious.
Rename special variable and move its name to constant.
Mark internal classes as internal. Add InternalsVisibleTo attribute.
Remove assembly alias for Travis build.
Merge pull request #130 from ForNeVeR/external-gui-process

Proper process input/output blocking
Merge remote-tracking branch 'origin' into CommandLineRun