Shrank git tutorial images.
Fleshed out new developer documentation.
Cleaned up documentation.
Fleshed out new developer documentation.
Fleshed out developer documentation.
Fleshed out new developer documentation.
Prepared Beam and Beams for __slots__.
Fixed doctest in freezeThaw.
Beam and Beams are now slotted.
MeterTerminal and MeterSequence are now slotted.
Microtone is now slotted.
Accidental is now slotted.
Derivation is now slotted.
StreamStatus and Tie are now slotted.
Groups is now slotted.
Fix one reference to SVN in usingGit.rst