This pull request allow a user to redefine default maven colors with some java properties.

For example one can edit his ~/.mavenrc with the following:

MAVEN_OPTS="-Dstyle.info=cyan -Dstyle.warning=bold,yellow"

Possible values are (case insensitive):

• colors
  • BLACK
  • RED
  • GREEN
  • YELLOW
  • BLUE
  • MAGENTA
  • CYAN
  • WHITE
  • DEFAULT
• attributes
  • BOLD

Possible keys are (case sensitive - always lowercase):

• style.debug
• style.info
• style.warning
• style.error
• style.success
• style.failure
• style.strong
• style.mojo
• style.project

This list is based on MessageBuffer.java API and could evolve until final release.

Additional note about tests: as configuration is handled into one single enum thus testing with java property is merely impossible. Enum Style is already loaded when test is starting.