Merge pull request #30 from s-ludwig/fix_null_pointer_access

Fix null pointer access when iterating over empty arrays

iOS compilation fix

- Works on 64-bit systems

- Compiles with the latest DMD without warnings
- The whole library, with the exception of the "extending" module, is now reentrant
- ErrorValue and derived exceptions now carry proper error messages

Merge test branch into master

Merged test to master

First D2 Version

version 1.16

version 1.15