Each R package should include ../../math/R/Makefile.extension, which also
defines MASTER_SITES. Consequently, it is redundant for the individual
packages to do the same. Package-specific definitions also prevent
redefining MASTER_SITES in a single common place.
Colored terminal output on terminals that support 'ANSI' color and
highlight codes. It also works in 'Emacs' 'ESS'. 'ANSI' color support
is automatically detected. Colors and highlighting can be combined and
nested. New styles can also be created easily. This package was
inspired by the 'chalk' 'JavaScript' project.