[PATCH 01/27] Add utilities for encoding BTLVs and CTLVs.

[Denis Kenzior]

Hi Andrew,

> This version merges ber_tlv_builder_next and _set_tag into one function,
> same for comprehension tlvs.  The ber_tlv_iter and ber_tlv_builder
> structs are not merged because the pointers in _iter need to be const
> else ugly casting is needed.

So I applied the first 21 patches in this series with some cleanups in between. 
All the unit tests still pass, but please recheck that I didn't screw 
something up.

Regards,
-Denis