Added option to suppress usage of TAUCS even if it is available.

6 jobs for taucs_suppression
Status Job ID Name Coverage
  Test
passed clang-c++11 #4631
Linux

00:05:25

passed clang-c++98 #4633
Linux

00:05:38

passed gcc-c++11 #4630
Linux

00:05:58

passed gcc-c++98 #4632
Linux

00:04:42

passed macos-c++11 #4634
Apple

00:02:08

passed macos-c++98 #4635
Apple

00:03:22