Rewrote the hosts plugin, added tests and ipv6 support
cmake: require Boost for tcl plugin

Look for Boost and enable the tcl plugin only if found, as it is used
there.

Also, make use of the Boost include directory, so a Boost installation
in an own path can be used.
tests: fix maximum uchar boundary

Do not overflow when accessing to the trie internal; having N as array
size means that N-1 is the maximum index accessable.
Fixed the check_real_world test
Merge pull request #94 from pinotree/trie-index

tests: fix maximum uchar boundary
Merge pull request #93 from pinotree/tcl-boost

cmake: require Boost for tcl plugin
Merge pull request #92 from fberlakovich/hosts-ipv6

Rewrote the hosts plugin, added tests and ipv6 support