Add donate button to documentation start page
Add note about Cython to development docs
Tweak installation guide a bit
Cleanup documentation start page
Fix typo in developer docs
Make simple "make" only build the extension

...instead of also building the docs and running tests.
Drop 'make dist' target
Make the "make" output more verbose
Add warning about running Cython in installation guide
Don't check iterator validity twice in a row
Ensure prefixed reverse iterators don't step past start key

See issue #9.
Release GIL when calling .Prev() on iterators
Update NEWS
Bump version number to 0.3
Post-release version bump
No reason to use UTF-8 encoder for ASCII only strings
Skip Unicode name test if file system does not use UTF-8

Fixes #10.
Rename variable in unit tests
Fix typo in example in user guide
Add optional 'default' argument for .get() methods

All .get() methods now accept an optional 'default' argument, just like
dict.get(). Also updated tests and docs.

Fixes issue #11.