WURFL XML is no longer free, so fix the tests to git-clone the last freely licensed version from github

This introduces an environment variable USE_FREE_WURFL which defaults to true. I deliberately haven't
bothered pointing the wurfl code to a working URL containing the current WURFL xml, so we're still broken out of the box...
fix POD to reflect WURFL data license changes
fix Changes line a bit
fix usage of File::Temp::tempdir
fix my bad assumption in tests about how wurfl_url works
fix tests not building SQLite tables with USE_FREE_WURFL
fix the sense of is( $got, $expected) in tests
make tests a bit more flexible/reliable.
80 cols in tests
fixup pod typo
add some logging that doesn't stomp all over STDERR
stop trying to create temporary directories with valid wurfl_home
make the tests a bit smarter
Add timing tests
fix the test script to set LIKE-friendly indexes; compare incremental/binary search methods
implement binary search. Broken _incremental_fetchall, will kill on next commit...
fix tests, they were n^2. Don't use wurfl ->set/get hack. Kill _incremental_batch
fix timing tests. shouldn't be including time to create new Mobile::Wurfl
add two shorter tests

1) canonical_ua: 'LG-KU970/v1.0'
canonical_ua_binary      714/s                       --                     -14%
canonical_ua_incremental 833/s                      17%                       --

2) canonical_ua: 'Mozilla/5.0 (Linux; U; Android'
                           Rate canonical_ua_incremental     canonical_ua_binary
canonical_ua_incremental  455/s                       --                    -55%
canonical_ua_binary      1000/s                     120%                      --

3) canonical_ua: 'Nokia3600'
                          Rate canonical_ua_incremental      canonical_ua_binary
canonical_ua_incremental 200/s                       --                     -64%
canonical_ua_binary      556/s                     178%                       --

4) Failed test 'got a canonical ua for uberlong_ua_string'
                           Rate canonical_ua_incremental     canonical_ua_binary
canonical_ua_incremental 6.68/s                       --                    -99%
canonical_ua_binary       769/s                   11415%                      --
test comments