0.4.5

• Improved wording of some warning & error messages
• Fixed excessive "duplicate local declaration" warnings
• Cherry-picked some Lua commits, so the following Lua bugs are now fixed:
  • 'break' may not properly close variable in a 'for' loop
  • error message in 'table.remove'
  • 'utf8.codes' accepts spurious continuation bytes
  • Negation in constant folding of '>>' may overflow
  • stack overflow with nesting of coroutine.close