ABSTRACT SYNTAX TREE
This commit focus its attention on the the development of 
1) DOCUMENTATION: adds some dot files in side dot folder. Adds some dox
files in dox folder. syntaxTreeExplained.c is a stub page to explain
deeply how the file syntax.y works (work in progress). Adds some example
in the directory docs/examples. Adds documentation in various files.
2) CONCEPT: adds "semantic rules" file (just a STUB) to explain the
concept behind SOL semantic module.
3) LEXICAL: adds the forgotten token TK_IN. The bug #1 present in my
last commit is now solved: i solve it by removing the "+" symbol on
real/int number. For strConst flex now use initQuotedString, that
automatically cut off \" character in fist and last position.
4) SEMANTIC: adds uthash.h, an header library retrievable from
http://troydhanson.github.io/uthash/. this header implements a flexible
C hash table. 
5) SYNTAX: changes the output of the graph built by
parserToolComputeSyntaxRecursive(). Changes printNodeType() string ouput
(not NT_/T_ prefix anymore). In syntax.y adds some
documentation/reorganize the entire file to be more readable. The
terminal representing the operatoris (+,-,*,/,in,>,<,>=,<=,==,!=) are
now node created under NT_REL_OP/NT_HIGH_BIN_OP/NT_LOW_BIN_OP
excetera...
6) TEST: update syntax-test
7) MAKEFILE: adds valgrind to the suggested program to be installed