Don't install libmmdbtest
Minor clean-up
Make ip_version a uint8_t

I don't see IPv256 coming out any time soon
Rename record_info struct to record_info_s for consistency
Put string error in diag, not mmdb error code
Add an IPv4 start node cache - all tests pass
Run uncrustify on code
Don't regen prototype for strndup in maxminddb_test_helper.c
When we calculate the IPv4 start node, we also need to know the netmask where we found it

This fixes the case of when a database has a subnet that contains the entire
IPv4 search range, for example ::/64.

Added tests for this.
Fix typo in README.md
Add an explicit error when someone attempts to look up an IPv6 address in an IPv4-only database.
Actually check for all the headers we use

Removed useless comments
We're not using anything from assert.h
mmdblookup.c is not using assert.h
We also need libgen.h
Added a number of tests for the Xget_value functions

I found a bug where looking up an invalid path did not properly set
entry_data.has_data to false. This is now fixed.
Add more debugging output
Check the return value of recursive calls to skip_map_or_array
Add a failing test for the pointer bug reported in https://github.com/maxmind/libmaxminddb/issues/2
Add new test file to t/Makefile.am