It seems impossible to ensure that blocks and line drawing glyphs
align without visible gaps for all combinations of arbitrary font,
size and width/height scale factor.
This commit adds options to render most of the lines/blocks and
braille codepoints without using the font such that they align
perfectly regardless of font, size or other configuration values.
Supported codepoints are U+2500 - U+259F except dashes/diagonals,
and U28XX.
The lines/blocks data is stored as 16-bit values at boxdraw_data.h
boxdraw/braille are independent, disabled by default at config[.def].h
Avi Halachmi (:avih)
