level fixes

    - fix incorrect handling of INFO
    - allow logging to be disabled via OFF or DISABLED
    - more efficient level checking
    - flag MojoX::Log::Declare compatibility gotcha
    - test case-insensitivity
    - fix doc typos
make sure the module does what it says on the tin :-)

    fix the log-level functions e.g. trace(), debug() &c.

    these were previously hard-wired to always return 1,
    which meant that arguments were always evaluated and
    Log::Declare::log was always called; the log-level merely
    influenced whether the output should be printed.

    fixed (with tests) to ensure the expected short-circuiting behaviour
restore the namespace hooks + tests removed in the previous commit

    - and add a comment to prevent someone else making the same mistake!
    - also clean them up slightly: use fixed/static (but internally dynamic)
      subs rather than generating them anew for each import
bump version to 0.10 + update changelog
Merge pull request #4 from companieshouse/fix_levels_redux

- fix issue with trace, debug &c. always returning true/not short-circuiting
- fix INFO priority
- allow logging to be disabled via OFF or DISABLED
- more efficient level checking
- flag MojoX::Log::Declare compatibility gotcha