Add a predicate to restrict has_base_url

This preserves the previous behavior of ->get() failing on an invalid
url. The base_url property should only kick in if it's specified during
construction to prevent action at a distance for users who aren't aware
of the attribute.
Reorganize new_from_caps documentation
Add $method to debug statements
Bump version
Conform with previous method of handling no content successful responses
Fix #136: Accept 200 as a passing status code for window size fns
Remove errant debug statement
Check for defined-ness of value instead of its truthiness

In some cases, the value is 0, like when returning whether or not a
checkbox is selected.
Move no server error message test to assuage the recorder
Unregister PSGI hook to let final tests run normally
Add deprecation note about WebElement::describe (see #144)
Update readme note about addressing the 2.42.x issues
v0.2002

        [BUG FIXES]
        - #135, #136, #142: Fix compatability issues with JSONWireProtocol changes in 2.42.2

        [NEW FEATURES]
        - Add an optional base_url parameter for automatic concatenation in get/get_ok
Normalize quotation convention in Commands.pm
Reindent whitespace in webelement.t
Fix #144: remove describeElement tests
content_like should not throw away description
Spruce up record.pl with a few more helper subs
Move scaffolding out of test section
Revert "Fix #135 : catch the new responses from Selenium 2.42"

This reverts f22f548 and 5d11c36. As discussed in #145, this solution
does not work as it interferes with some endpoints that expect to be
able to return false by indicating "" as their return value.

These fixes would catch that "" and return a non-empty string, which
would in turn evaluate to true.

Conflicts:
        lib/Selenium/Remote/RemoteConnection.pm