Handle ~ in '.' command. Fix #120
Update ARC disassembler and add support for compact arc

Source from https://github.com/foss-for-synopsys-dwc-arc-processors
$ r2 -a arc -b 16 thumb.arc
Correct pointer calculation in arm ldr opcode
Minor visual fix for 'e io' issue reported by idwer on irc
Many enhacements for the lua bindings

Load module and cast core instance at startup
Requires latest valabind.
Add RCore::ncast api
Use pkg-config everywhere to fix lua plugin build
Fix install path for lua bindings
Export RCore instance to #!lua shell
Example:
  #!lua
  print(c.assembler.bits)
Handle '!' and '.' commands in #! prompt

'!' : used to run system commands
'.' : used to interpret a file
Merge remote-tracking branch 'upstream/master'