Use ITEM_UINT for tree class
Store array of net IDs with signal declarations
Assign net IDs to scalar signals
Assign nets from port maps
Add argument to --dump to print out net to signal mappings
Generate an LLVM table to map signal sub-elements to nets
Allocate memory for nets in rt_setup
Change _set_initial to pass a net ID rather than signal pointer
Modify _sched_event and _sched_waveform to use nets
Use _vec_load for scalar signals
Rename active_signals to active_nets
Remove struct signal from all rtkern code
Add IDEAS file to .gitignore
New support function _test_net_event for accessing 'EVENT, etc.
Fix signal array references
Fix 'LAST_VALUE
Add _last_event to implement 'LAST_EVENT
Remove signal structure from code generator
Fix failure of func5 test
Fix regression of func8 test