Unit test for argument parsing without script bug

Add a unit test to demonstrate the argument parsing bug that occurs when
no explicit build script is specified.

[skip ci] Intentionally broken unit test
Fix argument parsing without script bug

The ArgumentParser would check if the parse argument was an option, if it
was it would then use the default script convention and continue parsing
options. However, it would never actually parse the first option, so for
example:

    cake.exe -option1=value1 -option2=value2

Would result in `option2` being successfully parsed, while `option1` is
silently dropped.

I believe this went unnoticed because all the unit tests and the default
bootstrapper script explicitly pass in the build script.
Merge branch 'dbent-topic/fix_argument_parsing_without_script' into develop