Fixes macOS hsimple.C with gDebug>0.

Connection id can be used to provide client-dependent output
Also there is always master connection flag.
Use connection info in RFrame and RStatBox when processing ranges
requests

This object provided to RDrawable::Display() method as argument and
give contexts - canvas, sub-pad, primitive index. Same context made
available for RDrawableRequest

Fixes memory issue reported by ASAN. Thanks, Stephasan!

In some systems configurations chrome not allows to run HTML files,
which are situated in /tmp directory. Only if such situation detected,
try to place such HTML files into home directory

There are two major send operations - canvas snapshot and reply on
RDrawableRequest. To ensure fair handling, both are injected in send
queue. 

Provide generic Execute() for RDrawable class, 
allows to execute all methods markes as **MENU**
Later one can provides attributes changes via menu

Assign RCanvas, RPadBase and RDrawable to requests members,
which can be accessed in RDrawableRequest::Process() methods.
Use pointer for pad and canvas while shared_ptr is not possible for
RCanvas

Client can submit request to the server and can assign callback
to get reply. Requests are derived from dedicated class and via
sub-classing can get arbitrary access to RDrawable API

As first example, use RHistStatBox for this. When working online,
statistic will be filled by the server through such special requests

If drawable not changed since last update, just send dummy entry to
client. This ensure that client do not remove element from paint list

While painter used for bi-directional communication, it is required
to access non-const methods of RCanvas

Use version to detect which drawable need to be transfer to client
Idea to reduce transfer when only attributes of some objects are changed

In many places incldues are not required for the dictionary generation, 
therefore target_include_directories can be used 

Let use this enum in win32gdk to avoid direct dependency from
Gui library there

They were not really used, but were introducing wrong dependency

Like canvas->Show("pos:100,100 size:900x800")

Supported format like "1000x500"

Move several virtual methods to implementation file

Do not expose X to GUI classes - they should include TVirtualX.h only
when required. 

Logically such NoValue "hide" any previously specified values in RStyle

Attempt to create menu items for X/Y axis

Axes itself intergrated into histogram, but different drawing attributes
will be configured via RAttrAxis. This will include line, text, grid
attributes, but also log or invert scale

For many basic objects like RAttrMap or RAttrMap::IntValue_t such
typeinfo can be ignored.