Increase FcgidMaxRequestLen to 128MB to allow larger file uploads under
FastCGI.

The "Using GBrowse 2.0 to visualize and share next-generation sequence
data" paper by Lincoln Stein states "In cases when the file is more than
100 MB in size, GBrowse users are encouraged to use the software's
remote BAM feature." 128MB was chosen because it is the next power of 2
larger than 100MB.