support matrix
fix curret layout
support variable brackets
improve style, input system
show variable italic,
support \left, \right and AMS matrix,
fix key map
support back transition
split symbol correlation table
support candidate scroll, reduce bender prefix
support various style (input only)
support styled output
fix input interpreting rule
add forgotten file XD
refine glyph rendering code, support sqrt
support big operator
add glyphs
fix backspce key's function
refine LaTeX output a little, add code for Firefox
alter style command interpretation
review accessibility
IO -> Keyboard class