added: count() method
Standardrizing coding style.
Unnecessary require_once removed.
Fix typos
Remove unnecessary require statement.
No such class ArgumentException.
Update doc comments.
Iterator implements can accept any Traversable value.
Merge remote-tracking branch 'tanakahisateru/quality2' into devel
Merge remote-tracking branch 'amkt922/devel' into devel
	modified:   README.ja.md
Merge pull request #22 from amkt922/devel

Devel
closed #23 EqualityComparer added
Merge remote-tracking branch 'origin/devel' into devel
Some classes are moved into Ginq namespace, then require_once removed.
Merge pull request #26 from tanakahisateru/remove-require_once

Some classes are moved into Ginq namespace, then require_once removed.
fixed count() bug
added: average(), sum()
disused `use` deleted
Changed so that `join` and `groupBy` might use `EqualityComparer`