add more jQuery-style shortcuts

- has_class
- css
- attr
handle switch_to_frame for WebElementSet
more updates

- increase selenium version to 2.32
- add `wait_for` which waits for visibility/presence of a certain
element
- allow `wait` override locally in kwargs
- allow `highlight` disable
- use `ActionChains` instead of js hackery (same as PR #35)
- add `move_to_and_click` which is different from `click` since `click`
clicks at the center of the element, which is not always desired
oops… add tests
update documentation

Also add `type_keys` as a workaround for Chrome bug
https://code.google.com/p/chromedriver/issues/detail?id=290
typo...
add select/deselect_option, tests and docs (same as PR #40)
merge @davidszotten's property deprecation stuff
expose new move_to to elementset
fix indentations
add tests to make sure backwards compatibility
Merge pull request #42 from longlho/master

incorporate previous PRs and add some jQuery shortcuts