Included several patches submitted by @han6man: #106, #105, #104, #103, and #99.
Integrated #97 and #100. Sample project is updated.
Added splitter size customization.
Changed splitter control color. Fixed dock window factory loading issue.
Removed Extender as it is not flexible to add new themes. Added the ITheme derived classes to manage theme elements.
Added auto-hide window customization.
Added base class for themes.
Moved VS2003 theme related files. Added DockPanel.Theme property. Marked previous properties obsolete. Updated sample project.
Revised dock window loading to avoid crash on Mono/Linux.
Simplified ReloadDockWindows method.
Merge commit '1e0b82c4f4380dce710731986b36887aed74e86b' into development_3.0
Normalized line endings
#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.
Merged master to 3.0 branch
Fixed project files.
Fixed dock windows size calculation to avoid crash on Mono/Linux.
Fixed another crash on Mono.
Prepared alpha release.