Add locking when interposing

Adding in TLS a variable (enter) to check whether
we are invoking libc from internal libc functions,
or we linking to libc from outside
Refactor backtrace/logging functions
Update  locking to avoid deadlocks
Special handling of libc function used by dlsym internally
Update wrapped prototypes
Update identation
Add support for fd types
Print fd types on write/read
Better safeguard  with semaphore when backtracing
memset plays along
special handling on fork and jumps - no timing

speciasl handling of read / write
Use optimized libc memset
More performance tunes(FILE * in TLS)
Add Makefile for gnu interposition library
x86 logging without fprintf
Interpose on gnu extensions