src/export.cc: Implement export of passage info for DXF (untested).
lib/survex.pot,src/,tests/: Add support for anonymous stations,
which are indicated by a station name of '.'.
src/listpos.c: Fix compiler warning.
src/netartic.c: Use TSTBIT(w, x) instead of w & BIT(x).
src/readval.c: Whitespace tweak.
configure.ac,src/img.c: Avoid warning about redeclaration of round().
src/gla-gl.cc,src/glbitmapfont.cc: Add checks for errors when reading
the font file.
src/: Use wxValidator to simplify keeping svxPrintDlg member
variables and fields in the dialog in sync.