Merge pull request #3767 from laanwj/2014_02_tinyformat_errors_non_fatal

Make tinyformat errors raise an exception instead of assert()ing

src/tinyformat.h

@@ -109,7 +109,7 @@ namespace tinyformat {}
 namespace tfm = tinyformat;
 
 // Error handling; calls assert() by default.
-// #define TINYFORMAT_ERROR(reasonString) your_error_handler(reasonString)
+#define TINYFORMAT_ERROR(reasonString) throw std::runtime_error(reasonString)
 
 // Define for C++11 variadic templates which make the code shorter & more
 // general.  If you don't define this, C++11 support is autodetected below.