Fix wp8 datetime roundtrip issue

Fix wp8 datetime roundtrip issue, by Convert it to string instead of
DateTime object inside TryConvert function, which matches win8 behavior
and gives back correct output.
Merge pull request #24 from xqiu/master

Fix wp8 datetime roundtrip issue
Android SDK initial commit
Fix to use UTF encoding for httprequests
Added missing space
Source formatting
.gitignore for libs
Check for null callbacks
Removed android-support dependecy
Helpers for Single Values in queries. Removed HttpPatch class because of the changed of HttpClient to version 4.2.3
Single method callback
More simple value query helpers and source formatting
More helpers for arithmetic operations
InstallationID support.

InstallationID support.
Now the MobileServiceClient constructor requires a Context parameter to
be able to retrieve the InstallationID from the app preferences.
Support for Date comparison operators. Support for Null numbers in queries
Date field helpers for queries. Better support for queries without filters
Projection and query modifiers tests
Source formatting
Checked Long serialization. Fixes for Delete operation
Android quickstart