Remove duplicate function in lua-ast
Implement matrix indexing using AST generation

Remove the bytecode generation rules for matrix indexing and generate
standard Lua AST on the fly.
Simplify on-the-fly AST creation
Differentiate statements from expressions in Lua AST
Introduce mechanisms to add generated statements in AST

The mechanisms accumulate statements in the AST state. When a new statement
is generated the acculated statements are bound to the statement itself.
The statements are therefore recollected when a BlockStatement is formed.
Implement matrix indexing bound checks
Declare complex matrix "data" field as a complex array
Remove duplicate functions in Lua AST implementation
Implement "mutable" flag for variables in Lua AST
Fix problem with empty function's body

Fix issue:

https://github.com/franko/luajit-lang-toolkit/issues/2
WIP: first preliminary working version of relocating index checks

Still include debug messages and need some polishing.
Adapt build config on Windows
Fix error with incompete conditions in check index relocations
Merge with master 2.0 branch of LuaJIT2
Merge branch 'matrix-complex' into mat-safe-index
Factor out the operator priority table from the parser
Factor out code to evaluate arithmetic constant AST node
Preliminary implementation of string source code backend generator

Currently work in progress. It does not handle all the constructs.
The strategy need to be changed to group the lines and organize
indentation by function. This latter is a better approach to handle
function expression, currently not yet implemented.
Simplify source code generator for expression lists
Accept non local function declarations in AST and bc code generator

Previously non local function declarations were stored in the AST tree
as a function expression plus an assignment.