Strongly typed options support

* non builtins options require declaration using the decl command

* At the moment, only int and string options are supported, however
the goal of this change is to provide a consistent way to support
more complex options, namely lists and booleans
Add support for boolean options
simplify how string -> option conversion are written, free functions instead of template specialization
log to debug when make_regex_ifp catch a regex_error
fix ignored_files default value
remove commented line in ncurses.cc