Extend performance graphs

[ChristophWWagner]

The performance graphs for "forward projection" should contain a second (and maybe third) plot for x10 (and x100 respectively) vectors. To be explicit:
Current implementation is numpy vs. fastmat (both with one data vector per transform).
Proposed variant is: (numpy x1 vs. fastmat x1 va. fastmat x10 (vs. fastmat x100))

@SebastianSemper Incorporate this into the tex extraction scheme?

[SebastianSemper]

Should be a no brainer to add this to the plot generation in the new sphinx docu.