Removed `-v` option from `tar` command.

* bootstrap: Removed `-v` option from `tar` command because they are little
             useful in spite of excess output.
* gcc/jamfile: Likewise.
* clang/jamfile: Likewise.
* icu4c/jamfile: Likewise.
* isl/jamfile: Likewise.
* mpfr/jamfile: Likewise.
* mpc/jamfile: Likewise.
* opencv/jamfile: Likewise.
* openmpi/jamfile: Likewise.
* ppl/jamfile: Likewise.
* valgrind/jamfile: Likewise.