Allow getting many items at once
Parse deleted occurrences
Parse correctly the responses
Add support for modified events
Parse item attachements
Adding partial implementation of convert_id, for :hex_entry_id to :ews_id
Validate opts and use symbol params in convert_id
Cleaning up TODOs and other cruft
Making mailbox always required - though MSDN is not totally clear on this point
Forgot a comma
Fix another typo - just learned my test case wasn't picking up
Fix CalendarItem Template error in to_ews_item

self in this state is a Template::CalendarItem Object and not a Hash.
Add LegacyFreeBusyStatus for CalendarItem
Implemented basic timezone handling. Default zones can be set as context (EWSClient#set_time_zone) or override for start and end times. Implemented #get_time_zones to request all available time zones.
Separate the logging configuration from the setup

The configuration can still be loaded in its previous form by requiring
'viewpoint/logging/config'.

Resolves #121
Ability to pass options when deleting an item

Additional options such as :send_meeting_cancellations were already
supported in the core but there was no mechanism for passing them to
Item#delete!
Mod: Allow Inline Attachments
Mod: Update Method Documentation
Alias *field_uRI as *field_uri

When performing restrictions on a find you were required to specify the
field URI keys with a capitalized "RI" which looked a bit odd and was
easy to forget to do (extract taken from GenericFolder):

    {:is_greater_than_or_equal_to =>
      [{:field_uRI => {:field_uRI=>'item:DateTimeReceived'}},
        {:field_uRI_or_constant =>{:constant => {:value=>date_time.to_datetime}}}]
    }}

This commit aliases the methods with lowercase equivalents so that the
above can be specified like this with no other changes:

    {:is_greater_than_or_equal_to =>
      [{:field_uri => {:field_uri=>'item:DateTimeReceived'}},
        {:field_uri_or_constant =>{:constant => {:value=>date_time.to_datetime}}}]
    }}
Introduced response error hierarchy

In order to be able to distinguish between types of error more easily,
an error type hierarchy was introduced. The response itself is embedded
within the errors with helpers for accessing the status and body more
easily.

This also introduces a special case for 401 Unauthorized.