Task-number: QTCREATORBUG-2912

Mis-merge?

Only useful for the compiled dumpers, and I have not used it for a while.

Reviewed-by: dt

Reviewed-by:  hjk

This removes the remove/set flicker in most single stepping cases.

Even if no engine is running.

Do not drop stack index in resetLocation (which is called
when switching). Do not switch to source unless we have
the file.

Reviewed-by: hjk

Rubber-stamped-by: hjk

get away from argument stringlists. instead, use native shell command
lines which support quoting/splitting, environment variable expansion
and redirections with well-understood semantics.

Task-number: QTCREATORBUG-542
Task-number: QTCREATORBUG-1564

For Breakpoint data manipulation.

Reviewed-by: hjk

The breakpoints are now (fairly) tightly guarded by the BreakpointHandler.
Engines and Views are only supposed to refer to them by id. They also have
individual states now. The breakpoint data is split into a "user requested"
"fixed" part in BreakpointData and the engines' acknowledged data in a new
struct BreakpointResponse.

TODO: Move m_state and m_engine members to BreakpointResponse. Fix regressions
in the marker handling.

Reviewed-by: hjk

Since all the debuggers are implemented in the debuggerplugin, that's a
natural place to put the action.

There's  some 'external' and some 'internal' part now. Other plugins
are only supposed the external interface.

Regression from 2.0.1

Rubber-stamped-by: hjk
Acked-by: Arvid Ephraim Picciani <arvid.picciani@nokia.com>