Implement two-pass bytecode reader

Useful to read kgc, knum , uv and debug section before the bytecode
instructions. It is needed to display bytecode instructions with
complementary information like "luajit -bl" does.
First implementation of bytecode instructions constants lookup
Print function name:firstline in bytecode decoding
Implement jump's target PC highlight in bytecode dump

Reproduce the same behaviour of LuaJIT. A symbol => is used to mark the
instructions that are target of a jump instruction.

The targets are determined by reading the bytecode instructions'
section in the first pass.
Add some comments about the bytecode decoding module
Add copyright informations in bytecode decoding module
Use a metatable to create printer objects
Implement simple listing mode in bytecode decoder

The simple listing mode print the same results of "luajit -bl".
Improve bcread module to write output in a specific file
Implement support to natively support -b options

Support all the options that LuaJIT supports plus the "-bx" to print
extended information side-by-side with bytes hexdump.

The bytecode string is generated by the language toolkit using the
builtin lexer, parser and bytecode compiler.