#91 - Ability to disable doubleclick to dock

A new property was added to the FloatWindow, DoubleClickTitleBarToDock,
to allow disabling the behavior of redocking a float window when double
clicking the title bar.  Also converted WndProc to a switch statement
for better readability and negligible performance.
#82 - Fix docking indicators in TopMost case

The article referenced by DragForm specifically mentions the need to
make it TopMost, but a note in the comments of DragForm said it wasn't
necessary. It is necessary.
Normalize line endings

No functional changes included in this checkin, this is simply to
normalize the line endings so that git diffs are useful again. This
appears to be a relatively new change from github requiring the addition
of the .gitattributes file.
#78 - Fix ObjectDisposedException in sample

When loading from XML the explicitly referenced controls were not being
recreated (like the toolbox, etc; where there is a private member
holding a reference to the form).  Solution is to recreate these forms
before attempting to load from XML, just as load from code is doing.
#69 - Restore support for multiple UI threads

Make the local windows hook unique per thread, to ensure a hook is
installed for each UI thread in the application using the DockPanel.
Remove unnecessary locks

There is no reason to use a monitor or any other thread synchronization
mechanism in this library.  WinForms are inheriently single-threaded and
the dockpanel can only ever be accessed from the thread on which it was
created.
#119 Initialization of Content's AutoHidePortion

When a DockContent is docked left, right, top, or bottom, the
AutoHidePortion will be initialized to the value of the respective
area's portion.  This allows the AutoHide to take on a fixed-size sizing
whereas previously it would always use a percentage sizing, starting at
25%.
Made undenoted sln the most recent VS version

We're versioning off old solution files for past versions of Visual
Studio (even though it's easy to change, there are no material structure
changes), but have been leaving the "plain" solution file as the old
VS2008 version.  Rather than explicitly version the current version, let
the "plain" version be the current solution file, with old versions
denoted in the file name.
#115 - Remove use of tabs for indentation

There's religion, politics, and tabs vs spaces.  Regardless of your view
it should be consistent, and since I'm implementing the change we're
going spaces.  If we need justification beyond my personal preference,
this is the default in Visual Studio.
Added pull request from lockszmith to add an event to the DockPanel that
will be raised when the value of the AutoHideWindow's ActiveContent
property changes.
#123 - Require click to show autohide content

Opt-in feature to require a tab to be clicked on to show autohide
content vice the current behavior of showing on hover.
#130 Refresh pane when setting CloseButtonVisible
2.8 final.
Added brackets to fix #71.
Fixed #129.
Merge branch 'master' of https://github.com/dockpanelsuite/dockpanelsuite
#130 Fix null reference exception when setting CloseButton while the content is hidden.
#138 When showing a content, prefer to place it in the active pane, otherwise default to the first available.
#128 - In the sample application, disable "close all but this" when there are no documents.
#128 - In the sample application, "Close All" should only close documents.