Add many new features and code cleanup

Have added better handling of local function definition and code
generation of numerical for loops.
Add pass which calls new luerl_comp_locf
Do new frame classification and add genereic for loops
Convert do_repeat and do_while to use loop_block
Add unpack for Lua 5.1 compatibility

Added to luerl_basic and just calls luerl_table:unpack
which has been exported.
Expand NOTES
Save current status of compiler/emulator
Add proper filename handling to compiler

Extend the top-level compiler state with fields for filenames.
Follow 'stmt' name convention and use new records
Remove _ENV as first argument to chunk
Allow backquoted newlines in literal strings
luerl_emul:get_table_key/3 always returns single value
First working version of the new engine
Convert to use Apache License, Version 2.0