Imp: Dataprovider for URL-resolve tests.

Added a dataprovider and a helper for dataproviders to
externalize fixtures incl. Net_URL2 options.

- new Net_URL2Test::_translateOptionData() helper
- added @covers notation.
Imp: Tests: @covers + Typos

- @covers added where edited.
- Wrong named test function renamed and moved to friend.
Regression test for Bug #17036
Chg: Net_URL2::testQueryVariables()

Test was originally introduced related to Bug #17036, but was bogus. Now
turned into coverage test for that routine to test the working parts.
Fixed #17036: Brackets broken for query variables

When OPTION_USE_BRACKETS was used (true, default), query string
key/value pairs were not properly parsed if the key contained more
than one bracket pair.

This has been fixed.

OPTION_USE_BRACKETS false was not affected.

Brackets are now properly parsed. In difference to PHPs own
variant, Net_URL2::getQueryVariables is binary safe and does
allow spaces and dots as well as null-characters in both key-
names (variables) as well as array-keys - both url-encoded or
url-decoded.

Steps done:

- Wrote private helper methods that are able to follow PHP's
  parse_str() pattern to parse a query string into an array.
- Fixed Bug #17036 in NetURL2::getQueryVariables()
Imp: Tests for getQueryVariables()

Improvements on the test-coverage of Net_URL2::getQueryVariables() and
its new helper methods.

- A dataprovider has been added
- Many fixtures
- Coverage greatly improved
- Test method renamed to better reflect for which method it is
Interim: Introduce variables.