MC CFG: Add a getter for MCDataAtom's data array.

While there, switch to new-style documentation.
MC CFG: uint64_t -> size_t for vector size.
MC CFG: Remap enough for the inserted instruction.
MC CFG: Don't insert preds/succs again.
MC CFG: Keep pointer to parent MCModule in created MCFunctions.

Also, drive-by cleaning around createFunction.
MC CFG: Add more MCFunction container methods (find, empty).
MC CFG: Add entrypoint address to MCModule.
MC: Refactor ObjectSymbolizer to make relocation/section info generation lazy.
MC: ObjectSymbolizer can now recognize external function stubs.

Only implemented in the Mach-O ObjectSymbolizer.
The testcase sadly introduces a new binary.
MC CFG: Add a few needed methods, mainly MCModule::findFirstAtomAfter.

While there, do some minor cleanup.
MC CFG: Split MCBasicBlocks to mirror atom splitting.

When an MCTextAtom is split, all MCBasicBlocks backed by it are
automatically split, with a fallthrough between both blocks, and
the successors moved to the second block.
MC CFG: Add MCObjectDisassembler support for entrypoint + static ctors.

For now, this isn't implemented for any format.
MC CFG: When disassembly is impossible, fallback to data bytes.

This is the behavior of sequential disassemblers (llvm-objdump, ...),
when there is no instruction size hint (fixed-length, ...)

While there, also do some minor cleanup.
MC CFG: Add "dynamic disassembly" support to MCObjectDisassembler.

It can now disassemble code in situations where the effective load
address is different than the load address declared in the object file.
This happens for PIC, hence "dynamic".
Add Mach-O entry_point_command declaration.
MC CFG: Add MCObjectDisassembler Mach-O implementation.

Supports:
- entrypoint, using LC_MAIN.
- static ctors/dtors, using __mod_{init,exit}_func
- translation between effective and object load address, using
  dyld's VM address slide.
MC CFG: Add an MCObjectSymbolizer in the MCObjectDisassembler.

Used to detect calls to function symbol stubs (future commit).
MC CFG: Use data structures more appropriate than std::set.
MC CFG: Support disassembly at arbitrary addresses in MCObjectDisassembler.
MC CFG: Add YAML MCModule representation to enable MC CFG testing.

Like yaml ObjectFiles, this will be very useful for testing the MC CFG
implementation (mostly MCObjectDisassembler), by matching the output
with YAML, and for potential users of the MC CFG, by using it as an input.

There isn't much to the actual format, it is just a serialization of the
MCModule class. Of note:
  - Basic block references (pred/succ, ..) are represented by the BB's
    start address.
  - Just as in the MC CFG, instructions are MCInsts with a size.
  - Operands have a prefix representing the type (only register and
    immediate supported here).
  - Instruction opcodes are represented by their names; enum values aren't
    stable, enum names mostly are: usually, a change to a name would need
    lots of changes in the backend anyway.
    Same with registers.

All in all, an example is better than 1000 words, here goes:

A simple binary:

  Disassembly of section __TEXT,__text:
  _main:
  100000f9c:      48 8b 46 08             movq    8(%rsi), %rax
  100000fa0:      0f be 00                movsbl  (%rax), %eax
  100000fa3:      3b 04 25 48 00 00 00    cmpl    72, %eax
  100000faa:      0f 8c 07 00 00 00       jl      7 <.Lend>
  100000fb0:      2b 04 25 48 00 00 00    subl    72, %eax
  .Lend:
  100000fb7:      c3                      ret

And the (pretty verbose) generated YAML:

  ---
  Atoms:
    - StartAddress:    0x0000000100000F9C
      Size:            20
      Type:            Text
      Content:
        - Inst:            MOV64rm
          Size:            4
          Ops:             [ RRAX, RRSI, I1, R, I8, R ]
        - Inst:            MOVSX32rm8
          Size:            3
          Ops:             [ REAX, RRAX, I1, R, I0, R ]
        - Inst:            CMP32rm
          Size:            7
          Ops:             [ REAX, R, I1, R, I72, R ]
        - Inst:            JL_4
          Size:            6
          Ops:             [ I7 ]
    - StartAddress:    0x0000000100000FB0
      Size:            7
      Type:            Text
      Content:
        - Inst:            SUB32rm
          Size:            7
          Ops:             [ REAX, REAX, R, I1, R, I72, R ]
    - StartAddress:    0x0000000100000FB7
      Size:            1
      Type:            Text
      Content:
        - Inst:            RET
          Size:            1
          Ops:             [  ]
  Functions:
    - Name:            __text
      BasicBlocks:
        - Address:         0x0000000100000F9C
          Preds:           [  ]
          Succs:           [ 0x0000000100000FB7, 0x0000000100000FB0 ]
     <snip>
  ...