v0.2.0

First release of my fork.

The evolutions are the following:

• Log levels re-ordering
• C++ support
• Log levels renaming to avoid conflicts with Syslog
• Code indentation changed to 4 spaces
• Added doxygen-style documentation for all functions and structures
• Log levels enum converted to a typedef
• Ability to configure library with the 'log_conf.h' file
• Renamed 'udata' variables in code to more meaningful
• Added sample source files
  • basic Is a basic example, to log to stdout and to a file
  • callbacks Is a minimal example using callbacks with different log levels
  • threading Shows a threading example