Large number of changes

Added common.h and common.c. These files contains common définitions,
such as a boolean enumeration (true and false) and an error logging
function called logError(), which out put message and file/name data
in the standard error output (stderr). See Doxygen documentation for
more informations.

Added Doxygen documentation for the XML Parser.

Restructured function using the same style used by Code::Blocks'
C parser (character '*' position when used with pointer).

Added other Code::Blocks files in .gitignore.
try resolving merge conflict on .gitignore