This replaces the (de facto) singleton engines and data handlers by classes
that are instantiated per run. The DebuggerRunControl will now create an
object of (a class derived from) DebuggerEngine that contains all the relevant
"dynamic" data.

DebuggerManager is no more. The "singleton" bits are merged into DebuggerPlugin,
whereas the data bits went to DebuggerEngine.

There is no formal notion of a "current" DebuggerEngine. However, as there's
only one DebuggerEngine at a time that has its data models connected to the
view, there's still some "de facto" notion of a "current" engine. Calling
SomeModel::setData(int role, QVariant data) with custom role is used as the
primary dispatch mechanism from the views to the "current" data models
(and the engine, as all data models know their engine).

Change the WatchWindow handling to be based on quint64 addresses to
ensure proper function. Changed roles and added one role to the
watchmodel to obtain addresses and pointed-to addresses. Add some
fiddling to parse out addresses from debugger values.
Add menu options. Make sure only one watchpoint per address is added.

Works only with gdb/Python so far.

Reviewed-by: hjk

Task-number: QTCREATORBUG-1139

- Do not reformat boolean values (true,false) as hex/oct.
- char/unsigned char types (cdb/gdb): Chop off the quoted
  printable character output by the debugger, pass around integer
  only and append the character ourselves in the watchhandler,
  making reformatting as hex/octal work.
- cdb: Check format correctly (fix values output as plain integer).
- cdb: Kill needless warning produced by reformatting output of out-of-scope
  variables.
- cdb: Display exceptions in the status bar as non-intrusive crash notification.

Reviewed-by: hjk

The original logic was faulty but worked better in the presence of the
original "extra layoutChanged()" hack which is replaced now.

Brace for impact...

Only revert stuff that is linked to fast string concat.

This reverts commit e70530c5. It
did break builds on older gcc versions (gcc 4.1.2 64 bit Linux,
gcc 4.0.1 on Mac OS X):

parser/qmljsgrammar_p.h: In static member function ???static int
QmlJSGrammar::nt_action(int, int)???:
parser/qmljsgrammar_p.h:188: error: ???QmlJSGrammar::<anonymous enum>???
is/uses anonymous type
parser/qmljsgrammar_p.h:188: error:   trying to instantiate
???template<class T> struct QConcatenable???
...

Split for testing/scripting purposes.

QString: Use QChar where appropriate.