Revert "Customer Support API"

This reverts commit 49751cd81dcd759324f8918ff57924a75aa8c131.

- because the customer support api will soon be no more
Merge pull request #79 from danhaller/remove-customer-support-api

Revert "Customer Support API"
Remove IsServerError as it's not used
and we may do it differently if/when we revisit this
Simpler message on NonXmlResponseException
"Error deserializing xml" implies that we used a deserialiser which is not so.
This has caused some confusion
Merge pull request #83 from AnthonySteele/XmlErrorMessage

Simpler message on NonXmlResponseException
Add in the response cache to the fluent api
Merge pull request #82 from AnthonySteele/remove-server-error

Remove IsServerError as it's not used
only cache the response if it wasn't from cache
Updated gitignore to remove .DotSettings
Fixed broken tests
Merge pull request #86 from gregsochanik/fix-tests

Fix broken ResponseParser tests
Merge pull request #85 from AnthonySteele/cacherefactor

Refactor to caching in the API wrapper
Tests on the FluentAPI's use of the cache.
Merge pull request #88 from AnthonySteele/cachetests

Looks good to me!
automated package build and version number increment to 8
UsingCache needs to be on the IFluentApi interface
automated package build and version number increment to 9
Two updates to the powershell build nuget package script
1) We can get the last package version from nuget with "nuget list SevenDigital.Api.Wrapper"
So we don't need to store it in a file (and do those annoying automated git commits).
2) make some methods with "CmdletBinding() param()" for safety as per http://stackoverflow.com/questions/16506899/powershell-is-ignoring-expression-after-function-call
Be defensive - FluentApi should not accept null httpclient or cache
as these will just cause exceptions to be thrown later
This provides a better error message
Merge pull request #90 from AnthonySteele/defensive

Be defensive - FluentApi should not accept null httpclient or cache