Multiqc: --sample-names file not parsed properly

[ewels]

As reported by @ohofmann on gitter:

Phil, I am struggling getting http://multiqc.info/docs/#bulk-sample-renaming to work. It seems to ignore the header line and skips straight to the first sample line to label the buttons.

Example file:
avner_names.txt

Looks like the file is formatted correctly, nothing obvious wrong.

The code should also probably warn if lines with length > 9 are skipped with no tab characters.

[ewels]

'doh!