Optimization for initial viable point

1. Currently local simplex method is always used in getViableInitPoint. This is often not sufficient and it's peanuts to run e.g. SA since the essential set of optimization methods is already available in IQMTools with an unified interface (in particular {high,low}bounds). Allow to specify OptimFnc option with a handler to (name of) one of these functions, and OptimOpts structure. Note: scatter search method requires additional package installation.

2. Moreover, change semantics of p0 in paramsSpec.txt to: if not viable, then try to optimize (currently returns an error).