Fixed string replace return value not being used in credit card filter.

Also tidied up credit card filter file.
Merge pull request #31 from AndyA13/master

Fixed string replace return value not being used in credit card filter.
CRLF cleanup
Added SentryHttp for HTTP contextual information
Capture server variables
Added WebTest project to test HTTP context capture
Added default page for capturing exception with HTTP context
Ternary assign to the "Http" property for tersness.
Renamed "SentryHttp" to "SentryRequest" and its corresponding "Http" property to "Request"
Ignore ALL_ and HTTP_ server variables
Capture HTTP headers
Capture HTTP cookies
Use Request.Url instead of Request.RawUrl
Capture POST data
Capture QueryString
Revert Formatting.Indented on JSON serialization.
The SentryRequest property should just be called "Request"
Added SentryUser so we can capture `sentry.interfaces.User`.
Delegated the instantiation of SentryRequest to a static method to improve readability in JsonPacket
Added properties to SentryUser