fix signed/unsigned warning
Support for -x option
params: add multi-level verbosity Now we can have --verbose=[012], so that the default (0) is still quiet, the easy verbose flag (--verbose or -v) is noisy but useful (1), and if you really want some extra noise, you can choose (2). Right now, there is some minimal extra noise in (2), but this may be expanded if we want more run-time debuggability, rather than recompiling with 'make debug'.
add traceanalysis support
Add yield block support. The idea is to not generate executions with yield actions. While preventing yields doesn't preserve livelock, under the CHESS assumptions, it does allow us to reach all states.
params: move model_params to header file