Major refactor of ReflectiveReader to do all reflection during initialize and minimize work during reading.
Fixed incorrect runtime reader type being written for EnumWriter<T>.
ContentTypeReaderManager now caches and reuses previously discovered ContentTypeReaders.
Merge pull request #2705 from SickheadGames/contentreader

ContentTypeReader Caching
Added image attaching for iOS Guide's Twitter

Added image attaching for iOS Guide's Twitter
Merge pull request #2718 from picobots/develop

Added image attaching for iOS Guide's Twitter
Avoiding loading content twice when a path is passed to us using different path separators or casing.
Fixed logic error.
Merge pull request #2722 from SickheadGames/CopyToOutput

Fixed logic error when copying a file to its output folder
Merge pull request #2721 from SickheadGames/FixPathSepAndCase

Fixed "Loading Content Twice" bug.
Fixed incorrect parsing of Number type.
Fixed cases of int.Parse() and float.Parse() to use the invariant culture.
Added a comment to clarify things.
Merge pull request #2724 from SickheadGames/mgfxculture

MGFX Fixes
Fixed possible ArgumentNullException in ContentTypeReaderManager.

ContentTypeReader.TargetType can be null, e.g. for ExternalReferenceReader.
Merge pull request #2725 from DigitalRune/contentreader

Fixed possible ArgumentNullException in ContentTypeReaderManager.
Remove unused usings (Targeting System.Linq)
Replace Linq usages with non-linq implementations.
Remove Linq usage in TouchCollection, don't allow null touches to be provided (matches XNA on WP7), provide our own enumerator implementation (matches XNA)

http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.input.touch.touchcollection.getenumerator.aspx
Merge pull request #2735 from danzel/tidy-linq

Tidy up unnecessary Linq usages