Version 0.2.0

Lots of improvements since 0.1! 🎉

Key changes:

• Added libdwarf as a back-end so cpptrace doesn't have to rely on addr2line or libbacktrace
• Overhauled library's public-facing interface to make the library more useful
  • Added raw_trace interface
  • Added object_trace interface
  • Added stacktrace interface
  • Updated generate_trace to return a stacktrace rather than a vector of frames
  • Added generate_trace counterparts for raw and object traces
  • Added generate_trace overloads with max_depth
  • Added interface for internal demangling utility
  • Added cache mode configuration
  • Added option to absorb internal trace exceptions (by default it absorbs)
  • Added cpptrace::exception, which automatically generates and stores a stacktrace when thrown
  • Added exception_with_message
  • Added traced analogs for stdexcept errors: logic_error, domain_error, invalid_argument, length_error,
    out_of_range, runtime_error, range_error, overflow_error, and underflow_error.

Other changes:

• Bundled libdwarf with cpptrace so the library can essentially be self-contained and not have to rely on libraries that
  might not already be on a system
• Added StackWalk64 as an unwinding back-end on windows
• Added system for multiple symbol back-ends to be used, mainly for more complete stack traces on mingw
• Fixed sporadic line number reporting errors due to not adjusting the program counter from the unwinder
• Improved addr2line/atos invocation back-end on macos
• Lots of error handling improvements
• Performance improvements
• Updated default back-ends for most systems
• Removed full tracing backends
• Cleaned up library cmake
• Lots of internal cleanup and refactoring
• Improved library usage instructions in README