Log Message:
(math/R-quantreg) Updated 5.99 to 6.00

- probably 5.100 means 6.00

5.100

1. The new `cholesky.f` (from 5.99) needed amendments to correctly pass
  'tiny, Large' to it e.g., such that package `cobs` tests pass.

2. Most naturally, extend the auxiliary R function  `sfn.control()` accordingly.