Replace ⋅ with ⋅ in correct font

[JLuc]

Optionaly replace all ⋅ glyphs (point median inclusif) with that glyph in a dedicated font (default = "Liberation Sans") and add a config to set that dedicated font in the book or in a chapter.

Warning : 2 different ⋅ exist and "Liberation Sans" only defines one of them !

• ∙ = BULLET OPERATOR = U+2219
• ⋅ = DOT OPERATOR = U+22C5

They dont look exactly the same : ∙⋅