corrected setField method of read/write documents

corrected setField method of read/write documents so passing in false but not null value does not mean field is removed

remove unwanted whitespace before php opening tag in Solarium_Client class

- refactored query helper, no longer tied to only the select query
- updated unittests and examples to reflect the refactored query helper

- phpdoc fixes
- zendhttp bugfix

- small docblock fix

- fixed docblock errors
- fixed ping query (resultclass was missing)
- fixed a unittest

Conflicts:
	library/Solarium/Query/Update/Command/Add.php
	tests/Solarium/Query/Update/Command/AddTest.php

- two small bugfixes for bugs found by the new tests

- added config mode support to Solarium_Client (including some required refactoring and new methods)
- improved unittests for config mode

- improved unittests

- improved unittests

- improved unittests

- improved unittests

- unittest improvements

- unittest improvements

2.0 traversable and clearable documents