[_m_a_x_p] rename 'allXMaxIsLsb' variable to 'allXMinIsLsb' for clarity's sake
[_m_a_x_p] rename 'allXMaxIsLsb' variable to 'allXMinIsLsb' for clarity's sake

The previous 'allXMaxIsLsb' name was misleading.
The 'allXMinIsLsb' boolean variable cooresponds to the head table's Bit 1.
This is set whenever all glyphs have the bbox.xMin equal to the respective
left sidebearing (and therefore "left sidebearing point at x=0").

googlefonts/fonttools,fonttools/fonttools