It is now possible to pass as 4th argument a list of objects to be added to the input list to further control
the PROOF behaviour:

   root [] TList *ins = new TList
   root [] ins->Add(new TParameter<Int_t>("MyParm", 3))
   root [] runProof("simple",0,4,ins)

the content of 'ins' will then be copied to the input list before processing.

The patch makes TProof::PollForNewWorkers virtual and adds an implementation of the same in TProofLite,
so that we can simulate dynamic startup, for packetizer testign purposes. The all thing is triggered
by the ROOT-rc

              'Proof.SimulateDynamicStartup'

which accepts a string value in the form "increase-step:max-num-workers", where 'increase-step' is the number
of new workers created at each call, and 'max-num-workers' is the maximum number of workers to start.
Once this is set, if a PROOF-Lite session with less workers than 'max-num-workers', during processing the
numbers of workers will be gradually increased to reach 'max-num-workers'.

The patch also re-organize the TProof code for dynamic startup to minimize duplications. In particular, the
part setting up the new workers environment has been separated into a new method SetupWorkersEnv, so that
it can used by TProofLite too.
Several bugs have been fixed in this code as a results of tests with examples requiring packages and loaded
macros, which were not used in the simple example used to develop this code.

Add missing possibility to control if after a request for changing a library or include path,
a log file is sent back.

Add possibility to force setting the number of workers. This is useful when only a maximum is known,
as in  the case of dynamic startup. The TParameter<Int_t> is called 'PROOF_DynamicStartup' and the value
is the maximum number of workers (wmax). It is assumed that the ordinals are 0.0 ... 0.'wmax-1' .

  AddWorkers is the method to add workers while running. Added a basic implementation
  for testing.
  The patch also moves fInput from TPacketizerUnit to TVirtualPacketizer to that it can be
  used more generally reducing code duplications.

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>

1. One could create now 'Text' item on the server side,
   which just disaplyed in the browser.
2. For text display MathJax can be used - one should
   specify 'mathjax' property for Text item.
3. Provide example with Text in httpcontrol.C macro
4. Support 'autozoom' draw option
5. Support _same_ identifier in items list
6. Remove default-ui class from droppable, hide nasty
   effects in StreamerInfo and Text display

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>

change name to TFormula::SetParameters(double*,int)  since it conflicts with TFormula::SetParameters(double,double)

the system will not find the associated pcm.

Based on #pragma cling load("libEvent") but compiler-compatible.
Fixes OrcJIT issue with availability of Event::Reset() which OrcJIUT needs to
have defined during object emission. Providing it as part of static init is thus
too late.

This also needed the implementation of rollback of nested transactions, so here
it comes.