Log Message:
jwm: update to 2.3.7.

Upstream changes:
(from http://joewing.net/projects/jwm/release-2.3.shtml#v2.3.7 )

Changes in 2.3.7 (20170721)

  * Made the modifier for dragging a window by clicking its contents
    configurable via the mask attribute of the MoveMode tag (issue #324).
  * Added group options for setting initial window position and size
    (issues #79 and #348).
  * Added the clicktitle and sloppytitle options for FocusModel, which cause
    windows to be raised only when the title or border of the window is clicked
    (issue #286).
  * Fixed scaling of icons in the task bar (issue #328).
  * Added the decorations attribute to TaskListStyle to allow setting different
    decorations on tray buttons and task list buttons (issue #330).
  * Fixed a bug with the nextstacked key binding (issue #335).
  * Improved support for 3-digit hexcode colors (issue #336).
  * Better aerosnap support on multiple monitors (issue #342).
  * Fixed a bug with multiple separators in menus (issue #343).
  * Fixed a bug with blank trays when there are full screen windows
    (issue #356).
  * Added the spacing attribute to Dock to allow adding space between icons in
    the dock (issue #357).
  * Added support for dynamic root menus via the dynamic attribute of RootMenu
    (issue #221).
  * Fixed an issue with 32-bit TrueColor visuals on some platforms.
  * Fixed an issue with menus and multiple monitors (issue #384).
  * It is (once again) possible to disable desktop switching by scrolling on
    the desktop using an empty root menu (issue #366).