The tlsf_control_functions.h and tlsf_block_functions.h
are moved to the root dir.
The tlsf.h header (the only public header has it contains
the public API) is kept in include folder.
The tlsf_common.h header is deleted and its content is
split accross all header files since this file was originally
containain the definition of structures such as block_header_t
and control_t that can now be moved to tlsf_block_functions.h
(respectively tlsf_control_functions.h).
