Check whether automatic addition of 'pthread' tag by TAU configure affects TAU Commander

[nchaimov]

For some configurations of TAU, the configure script forces pthread support on, which adds the pthread tag to the build.

We should check whether any of these configurations are supported by TAU Commander and, if so, either 1) adjust TAU Commander's tag generation code so that it add pthread for those configurations even if the tag was not explicitly added or 2) add constraints to the models to require pthread support be enabled in TAU Commander for such TAU configurations.