Added null checks for ModifiedDate and UTCDateModified.
Escape the URL parameters in BuildAuthorizeUrl.

In particular this means that the callback URL passed in to this function
and DropNetClient.GetTokenAndBuildUrl will be correctly escaped.
Merge pull request #91 from ewanmellor/modified-date-null-checks

Added null checks for ModifiedDate and UTCDateModified.
Merge pull request #92 from ewanmellor/escape-auth-url-params

Escape the URL parameters in BuildAuthorizeUrl.
Fix typo in readme.markdown

Endore -> Endorse
Implement GET /<version>/copy_ref/<root>/<path>.

This adds GetCopyRef, GetCopyRefAsync, and GetCopyRefTask to
DropNetClient.

It includes a new CopyRefResponse class.
Implement POST /<version>/fileops/copy using from_copy_ref.

This adds CopyFromCopyRef, CopyFromCopyRefAsync, and CopyFromCopyRefTask
to DropNetClient.
Merge pull request #96 from ewanmellor/copy-from-copy-ref

Implement POST /<version>/fileops/copy using from_copy_ref.
Merge pull request #95 from ewanmellor/copy-ref

Implement GET /<version>/copy_ref/<root>/<path>.
Merge pull request #94 from DavidDeSloovere/master

Fixed typo
Merge remote-tracking branch 'upstream/master'