Speed up filtering a bit
Project: disable minimal rebuild
Project: Add $(WXWIN)src to source search path
Overhaul and refactoring of symbol handling and proclists

Symbols are now identified by a number, rather than a string.
In some places, this number is now used instead of a Symbol*.
Using a numeric ID instead of a pointer allows us to persist
state across database reloads.

As a result, selections now persist across list refreshes,
and UI performance has been generally improved.

Cross-list references (e.g. ProcList->SourceView) have been removed
in favor of more explicit communication with MainWin. The code has
been overall simplified and clarified.
Refactor and optimize filtering and highlighting

Introduce a ViewState structure which caches filters and highlights
per-symbol.