Replace undefined function canCache with canCacheRequest

Probably a bug from previous refactoring, just caught it as I tried to override only the response can cache mechanism.
Merge pull request #397 from inssein/patch-1

Replace undefined function canCache with canCacheRequest
Fix #399
Updates LogPlugin to use Protected for $logAdapter

Changes $logAdapter in the LogPlugin from private to protected. This
makes it easier for people to extend from LogPlugin to make any needed
customizations and still have access to $logAdapter. Without this
change, if someone wanted to use $logAdapter, they will need to
duplicate the entire class instead of extending.
Merge pull request #401 from janiv/protectedLogAdapter

Updates LogPlugin to use Protected for $logAdapter
Merge remote-tracking branch 'thinkscape/hotfix/additional-parameters-cleanup'
Using already populated variable
Removing unused use
Fix fatal error in RequestMediator::writeResponseBody() when malformed response is recieved

https://github.com/guzzle/guzzle/issues/408
Visit children who have xmlAttribue first when building up xml
Minor tweak
Merge remote-tracking branch 'natmchugh/check-childen-have-attribues'
Tweak
Only exploding on header glue when not inside of a comma. Closes #411
Making mimetype guessing case-insensitive
Only injecting schema in models when specified in OperationResponseParser constructor. Models still always return a Parameter object when calling getStructure(), but this cleans up var_dump and var_export for most use cases. Closes #402
Adding a new line after debug model output
Changed test to show JsonVisitorTest::testAddsJsonHeader fail
Changed test to show XMLVisitorTest::testSerializesXml fail
Fix JSON and XML request visitors to set Content-type before body