Added RTLIL::Module::connect(const RTLIL::SigSig&)
Added RTLIL::Module::connections()
Added some missing "const" in rtlil.h
Changed users of cell->connections_ to the new API (sed command)

git grep -l 'connections_' | xargs sed -i -r -e '
	s/(->|\.)connections_\["([^"]*)"\] = (.*);/\1set("\2", \3);/g;
	s/(->|\.)connections_\["([^"]*)"\]/\1get("\2")/g;
	s/(->|\.)connections_.at\("([^"]*)"\)/\1get("\2")/g;
	s/(->|\.)connections_.push_back/\1connect/g;
	s/(->|\.)connections_/\1connections()/g;'
Manual fixes for new cell connections API
Merge automatic and manual code changes for new cell connections API
Added RTLIL::Cell::has(portname)
More RTLIL::Cell API usage cleanups