Introduces EXTTermCellGlyph and EXTTermCellLayout and removes EXTDotImageCacheKey in favour of makeCacheKey(). Image generation hasn’t been changed yet.
Teaches EXTImageTermLayer to draw unfilled squares besides filled dots.
Uses the spectral sequence default characteristic when the order of homology representatives is zero.
Uses the order of homology representatives to choose which glyph should be drawn: unfilled square for infinite order, filled dot for finite order.
Merge branch 'issue72'