Add support for line numbers in stack traces (Linux/Mac OS X only at this point)

* Add support for debug annotations on statement boundaries to the
  IR, to get accurate line/column information
* Use binary search to retrieve the function and line number for a given
  program counter
* Save the stack trace in the exception class and print it in v4
* Fix initial line number in QV4::Script to start a 1, just like the initial column
  in QQmlJS::Lexer also starts at 1

The native stack frame tracing is currently only implemented on Linux and Mac OS X.
The implementation for Windows using StackWalk64 is still missing.

Change-Id: I771fe44816397e29c69952772a772bf0d985236f
Reviewed-by: Lars Knoll <lars.knoll@digia.com>