Basic float support
Annotation
Tests at extended level
Integrate float into edn datum type, fixing bugging
Merge branch 'terml' into numbers
Merge branch 'master' into numbers

Conflicts:
	edn/tests/test_ast.py
	edn/tests/test_extended.py
Parsing of exact floating point
Failing test
Use ExactFloat for AST representation
Handle exact floats with no fractional element
Handle encoding from Decimal
Remove stale comment
Merge pull request #12 from jml/numbers

Floating point support