Let horizontal scrollabar overlay the client area

Increase Tree/Table client area height with scrollbar height.

451480: [Tree][Table] Horizontal scrollbar does not overlay content
https://bugs.eclipse.org/bugs/show_bug.cgi?id=451480

Change-Id: Ie4db982151c334ec132281fc5e9859bc1ef6e6dc
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Add supported widgets to RWT.HYPERLINK JavaDoc

447196: [JavaDoc] Update RWT.HYPERLINK JavaDoc
https://bugs.eclipse.org/bugs/show_bug.cgi?id=447196

Change-Id: I6d68ac17b453dec759ad82eeec4b357abdd2cccd
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Fix truncated content in forms Section

RAP supports four border edges since version 3.0M2. Display#map method
has been changed to respect this (use Control#getBorder instead
Control#getBorderWidth). As a result, the workaround for additional 1px
border introduced by the rounded titlebar in forms Section class
(override getBorderWidth method) does not work anymore.

Change the workaround by overriding the Section ControlThemeAdapter.

451524: [Forms] some missing pixels truncated in bottom of Form Section
Content
https://bugs.eclipse.org/bugs/show_bug.cgi?id=451524

Change-Id: I5c806483cf0dfa6ce3cc9f3b16089257ae4b4c2f
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Fix JS crash when forms Hyperlink widgets is used

Since RAP 3.0M1 forms Hyperlink widget is based on MultiCellWidget.
MultiCellWidget internally uses RWTQuery, which does not detect custom
widgets (not in rwt.widgets namespace) correctly. This leads to JS error
when element is appended to one of the cells.

Change RWTQuery#isWidget implementation to respect custom widgets (which
extend rwt.widgets.base.Widget) not in RWT namespace.

Change-Id: I32b64455596d10ea76e5c031c03cc3d4a54b9be0
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>