better build system checking for c++11 and adding to CXXFLAGS
Added author to doxygen documentation.
added author to sphinx documentation.
commented out incomplete section of sphinx tutorial doc.
Merge branch 'pcastell'

Conflicts:
	configure.ac
proper deserializer making using of iterators rather than buffers.
make end iterator for deserializer const, and add doxygen doc.
load deserialized objects directly instead of creating a temporary buffer.
add reasons why connect_input fail.
write tx data to disk in native format.
new style serializer using iterators.
deleted bdb backend (obselete).
switch to new serializer.
purged protobuf. introduced new hash_digest_list, short_hash_list and block_header_type. database is storing block directly on disk with hashes now.
remove misleading block comparison operator.
tidy up sliced_detail a little (not much).
updated doc for recent changes.
update reorg test.
assert that db ptr is good in db_open()
bugfix - detail hash wasn't getting recomputed when we change the header.