Update metadata, itemstack and add compare_block_status

[S-S-X]

• Added core.compare_block_status(pos, state)
  • Does nothing and always returns true,.
• InvRef, MetaDataRef and NodeMetaRef updated
  • Extended functionality a bit.
  • Fixed various problems.
  • InvList type removed, InvRef handles inventory lists completely.
  • Added InvRef:set_lists
  • Added MetaDataRef:from_table
  • Added NodeMetaRef:from_table
  • Added some tests.
• ItemStack updated
  • Added ItemStack:replace
  • Fixed various problems.
  • Added some tests.

Link to: #1 and #2
Also compare_block_status related: #34

[S-S-X]

Tested both Lua 5.1 and LuaJIT 2.1 with following projects:

• Advtrains
  18 successes / 0 failures / 0 errors / 0 pending : 0.079992 seconds
• Technic
  181 successes / 0 failures / 0 errors / 5 pending : 0.964132 seconds
• Technic CNC
  31 successes / 0 failures / 0 errors / 0 pending : 0.085864 seconds
• Technic Chests
  5 successes / 0 failures / 0 errors / 0 pending : 0.011047 seconds
• Machine_parts
  5 successes / 0 failures / 0 errors / 0 pending : 0.01535 seconds
• Metatool
  21 successes / 0 failures / 0 errors / 0 pending : 0.015995 seconds
• Sharetool
  15 successes / 0 failures / 0 errors / 0 pending : 0.012671 seconds
• Containertool
  10 successes / 0 failures / 0 errors / 0 pending : 0.012704 seconds
• QoS
  31 successes / 0 failures / 0 errors / 3 pending : 0.032126 seconds
• Beerchat
  23 successes / 0 failures / 0 errors / 0 pending : 0.041004 seconds
• Jumpdrive
  7 successes / 0 failures / 0 errors / 0 pending : 0.0111 seconds
• Mobs
  11 successes / 0 failures / 0 errors / 1 pending : 0.017619 seconds