To use multiple working threads. This entailed adding KiCad typedefs:
*) Add typedefs for MUTEX and MUTLOCK which mask the actual choices for the project.
*) Add FOOTPRINT_LIST::DisplayErrors( wxWindow* ) which is a single strategy for
showing aggregated load errors. Although what's there is only scaffolding
and needs a volunteer who knows HTML pretty well.
*) Ensure all callers of ReadFootprintFiles() use the new DisplayErrors() function.
*) Push utf8.cpp and utf8.h into common library for open use.
Eeschema: cleaning code. Start work to enhance annotation algorithm.
Already added an option to annotate using sheet number (sheet 1 uses numbers 100 to 199, sheet 2 uses 200 to 299..).
Works fine if deleting existing annotation, but needs work to be used when the existing annotation is kept .