fix bug in include file reordering

If file includes other file(s), but no file includes it, and it uses
classes after the inclusions, there would be a ClassNotFound error
raised. This is fixed now.

See [https://github.com/luke-gru/riml/issues/29]
add test for include reordering
fix edge case where file is get compiled twice

File gets compiled twice in edge-case where file from commandline
has same name as sourced file.