support color/xcolor/spotcolor packages

• On LaTeX, color names or expressions of color/xcolor packages
  

  can be used inside mplibcode environment with the command
  \mpcolor{<color expression>}.

v2.7.0

support dvipdfmx; new default cache dir

resepct show command

and fix a color bug

v2.6.0

Merge pull request #42 from dohyunkim/master

v2.6.0 for ctan

v2.5.3

Merge pull request #34 from dohyunkim/master

v2.5.3

v2.5.2: Merge pull request #33 from dohyunkim/master

v2.5.2

v2.5

Merge pull request #24 from dohyunkim/master

btex...etex in external mp files

v2.4

Merge pull request #23 from dohyunkim/master

v2.4

everymplb/everyendmplib & naked tex commands

Merge pull request #17 from dohyunkim/master

fix a bug wrt mp code parsing

transparency and shading; change wrt verbatimtex

Merge pull request #14 from dohyunkim/master

v2.2