corrections/additions in comments
concatenate prefix, message and colors into one string and call fputs() only once
add functions to enable/disable colors for each output stream
implement user defined callback funtions to handle formatted messages
add functions to check if color is enabled for a output
use guards instead of deeply nested if statements
fix errors in referenced ids intest cases
unify common functions for stream and function output
update README
don't use defines if LOGGER_ENABLE is defined
update (doxygen) comments
add doxygen configuration
yet another rework of prefix handling and add date prefix
adapt tests to new prefix format
add/remove spaces in the right places in prefix
reenable legacy defines for prefix formats
add functions to set/get the default prefix
corrections to disabled defines
switch back to pandoc tables
add test for changing standard prefix