CMakeLists: Add C99 Compiler flag

Signed-off-by: Robert Lehmann <lehmrob@gmail.com>
include: ringbuffer: Added functions for init and print

Add functions for inititating the ringbuffer and a function for printing
the ringbuffer.

Signed-off-by: Robert Lehmann <lehmrob@gmail.com>
gitignore: Update gitignore

Signed-off-by: Robert Lehmann <lehmrob@gmail.com>
src:ringbuffer: Implemantation of the init function

The init function for the ringbuffer is implemented. This functions
takes an pointer of an existing ringbuffer structure and the number of
elements which will be initialized. If an error occurs the functions
returns the errorcode. If the functions exits whithout an error it
returns zero.

Signed-off-by: Robert Lehmann <lehmrob@gmail.com>
utils: Initial commit

This file includes utility functions which are used from different other
files. By now the file only includes a function for printing the the
structure.

Signed-off-by: Robert Lehmann <lehmrob@gmail.com>
gitignore: Update gitignore
CMakeLists: Add utils.c to the source list
include:ringbuffer: Remove the print_buffer function
src:ringbuffer: Remove debugging output
test: Implementing the test for the current functions