Lua-Support: Minor bugfixes.

- The command ':LuaExecutable' accepts paths like "~/..." or "$HOME/...".
- Other bugfixes.
WorldView: Improved manpage viewer.

- Added opening of manpage using visual selection.
- Added jumping to options in manpages.
- Extended the menu.
- Fixed the global map created using 'g:WorldView_ManGlobalMap'.
- Internal changes.
Toolbox: Easy loading of additional tools.

- Added sub-menu "load additional tools" to load tools during a session.