plot labels not being passed properly from canSAS reader

[butler]

I noticed that loading a canSAS1D data set the axis labels only show units but not the label (1/A but without Q). This is also clear from data info. Further data from the ASCII reader not only provides the labes and the units it does so in a nice way to the plots using TeX such as:

{\AA^{-1}}

Note: All readers should be checked to be consistent at some point but canSAS reader probably needs to be correct for this release

[butler]

the missing label has been fixed. The inconsistency in format remains but is the subject of another ticket #601 so closing this one.