Byfl v1.3 for LLVM/Clang/DragonEgg v3.5.1

Given the amount of Fortran code I work with, I decided to keep Byfl's llvm-3.5 branch alive, despite LLVM 3.5 not being the most recent release of LLVM.

There have been a lot of changes since the last release of Byfl. The most major change is that there is no longer a build dependency on libbfd. Instead, symbol names are determined at compile time by reading LLVM's debug metadata. Other changes include support for building on OS X, a new -bf-inst-deps option that tracks instruction dependencies (i.e., which instructions' output serves as which other instructions' input?), and the output of a new "System information" table, which includes begin and end time stamps for the run.