Minor fixes to bandwidth tests

Two minor fixes on the issues spotted by @erodrigu and @abertoli :

• Fix the input rate of Sprucing (was 1 MHz, should be 100 kHz)
• Highlight "problematic" numbers in red in the table, a cell is highlighted if (temporary limit)
  • the rate is larger than 1 kHz
  • the event size is larger than 1 MB
  • the bandwidth is larger than 200 MB/s
• Fix dead links in the bandwidth test page by
  • removing comparisons.html page
  • making line-descriptive work for Spruce

cc @nskidmor