support added-tone chords, Cadd2, Cadd9, etc (was conflicting with Caug)
Add many pending test cases.
move testchords to testdata, and split into done and failing

	modified:   testdata/testchords
Support and tests for more chords inc C6/9, Cm7/+5.
add -Wall -fno-warn-missing-signatures to cabal ghc-options

this will get us (most) warnings when building with cabal
Add support for chords like Cm13dim11 (c.f. Cdim9)

I think the above should be written Cm13b11 or Cm13-11 but we're easy