Debugger: Adjustments to Jamfile.

- Remove duplicate instance of libshared.
- Add linker flags to not export symbols from linked in static libraries.
  Resolves an issue on gcc4 where symbols from libedit and libsolv would clash,
  leading to crashes.
- Add package kit-related headers and libraries.
Debugger: UserInterface enhancements.

Add hook to UserInterface to query if Debugger is currently being run
interactively or not. Add corresponding implementations in
{CommandLine,Graphical}UserInterface.
Debugger: Add initial support for automatically installing packages.

DwarfLoadingStateHandler now attempts to locate a matching package for the
missing debug information file. If one is found, the user is prompted to
install it. The actual installation process is currently handled by calling
pkgman, but this will be adjusted in future commits to either rely on
HaikuDepot in the graphical case, or to integrate the requisite functionality
directly so that proper download/installation progress can be shown.

In any case, this completes the low level functionality for ticket #10138,
leaving mainly presentation issues.