Added 'Clear Text' keyword for clearing the text value of a text entry element.
Added test for new 'Clear Text' keyword.
Renamed new 'Clear Text' keyword to 'Clear Element Text'

Renamed keyword to match corresponding and already existing keyword in the
Selenium2Library Java port. Update acceptance tests and removed invalid tests.
Fix url retrieval

See http://www.w3schools.com/jsref/prop_doc_url.asp
This refs #281
Merge pull request #334 from ombre42/url-in-window-info

Fix url retrieval
add default prefix and support prefixes with spaces
fix unit test for bad prefixes
Pass window.id through if not None
thank the thankless
Merge pull request #336 from ombre42/window-ids-unexpected-type

Pass window.id through if not None
improve doc for default locator prefix
fixes #200

Totally unrelated change I know.
typo in default strategy doc
Merge branch 'spaces-in-locator-prefixes' of https://github.com/ombre42/robotframework-selenium2library into ombre42-spaces-in-locator-prefixes

Conflicts:
	CHANGES.rst
Merge branch 'ombre42-spaces-in-locator-prefixes'
Removed unnecessary check on return value from _element_find.
Merge pull request #297 from emanlove/clear-text

Added new keyword 'Clear Element Text'