Make the LLVM detect script verify that the dynamic library actually exists.

Not deleted, because it's the only option for some other operating
systems such as FreeBSD or any other slightly exotic operating
system someone might try and run dolphin on.

This fixes detection of at least libenet via pkg-config, and I think
libpng via pkg-config pulseaudio via direct detection.

Also remove the NOT APPLE from the shared libenet check, because there's
no reason for it.

We require LLVM 3.4 minimum, so if the user has something older make sure to not attempt compiling.
Fixes issues #7858 and #7906.

- all files converted to unix line endings
- files from other subsystems and most of system have been removed
- include/SFML/System.hpp and include/SFML/Network.hpp modified to
  not include removed stuff
- IpAddress.*pp renamed to IPAddress.*pp to workaround git apply bug
  with case-only renames

$(llvm-config --ldflags) was passed to the compiler but it needs to be
passed to the linker instead (-L and -l flags).

I must have had a dirty cmake configuration which didn't encounter this issue.
Make sure we are using LLVM_DEFINITIONS to know where we are linking to libraries at.
Link against libLLVM-${VERSION}, the other one was linking us against static libraries...

Implements LLVM based disassembler for the debugger.

This will work for all of our platforms, x86, ARMv7, and AArch64.
Main issue with this is that LLVM's cmake files aren't correctly finding the LLVM install.
Not sure if this is Ubuntu's issue or not, it may just work on other operating systems.

We could potentially improve this, you can pass in a specific CPU in to the LLVM disassembler. This would probably affect latency times that are
reported by LLVM's disassembly? This needs to be further investigated later.