this is a start of a 'smart' run merging/splitting/inserting algorithm in the bidi layout engine and it is currently only enabled in the debug build. When it is debugged and finished, the bidi build will have only a marginally larger memory requirenments than the non-bidi build, and at least comparable, if not noticeably supperior, draw/refresh performance.
files: fp_TextRun.h/cpp, fl_BlockLayout.cpp, fp_Line.cpp Tomas
