Modbus: fix test: add missing filles and add Modbus source+build in GH CI

Modbus: add CI test + test project

Doc: re-organize existing, sketch outline, add SVGHMI intro.

Examples: add svghmi_json_table

SVGHMI: add "DISCARD:" prefix to force discarding an SVG element

SVG: fix HMI:Assign widget to properly handle single-letter variable names.

SVGHMI: Fix wrong documentation copy-pasted in HMI:Page.

SVGHMI: add FlatButton with no active or inactive elements.

SVGHMI: i18n: minimize warnings for incomplete/fuzzy/outdated translations

SVGHMI: i18n: fix .POT generation + other cosmetic fixes.

merge

Removed forgotten debug print.

SVGHMI: fix py3 consequences on i18n

merge

SVGHMI: Fix thumbnail generation.

Tests: update svghmi test project to py3 and erpc

IDE: Fix local runtime not starting on windows.
Consequence of updating ProcessLogger's argument handling.

Add credits for Czech i18n

Shows AboutDialog even if revisions.tx is missing

IDE: Fix encrypted ERPC: newer TLS, better error handling, re-add explicit ERPCS scheme, use sslpsk better.

merge

IDE: display contents of revisions.txt (put there by installer builder script) in About Dialog.

eRPC Server: fix exception at disconnect and reconnecting

Merge pull request #31 from martinpihrt/python3

Czech translation from Martin Pihrt

Create Beremiz_cs_CZ.po

Create Beremiz.mo

Fix SVGHMI build exception on windows: return bytes for inkscape path in docsvg.

SVGHMI: fix consequence of last change in ProcessLogger

Update requirements.txt

Remove forgotten debug prints

merge

Updates requirements.txt about forks of Nevow and sslpsk

Fix deprecated WX call producing warning.

Fix exception on right click, showing context menu.

GCC toolchain: Add {SYSROOT} substitution with support for whitespaces

Any instance of {SYROOT} string in config's CFLAGS and LDFLAGS is replaced by sysroot path obtained from "gcc -print-sysroot"

Fix argument lexer in ProcessLogger, replace it with shlex standard python module.

SVGHMI: Fix warning with WxPython > 4.x

docsvg: safer version checking of Inkscape

IDE. update genicons.sh to inkscape 1.1 command line

IDE: adjust Build and Clean icons colors.

Fix variable forcing. Now works with eRPC. PLCObject API changed.

Fix strings displaying as repr(bytes) in debug view.

Fix variable tracing in new eRPC interface.

Replace PYRO with ERPC. Work In Progress.

Fix blind replace ('text' into 'str') from py3 port

Fix settings URL: now '/' instead of '/settings'

Merge

SVGHMI: Fixes UI lifecycle problems

Was sometime showing HMI tree of previously closed project : no more module globals to store hmi tree.
C++ dead object exceptions happened when re-opening SVGHMI UI or building after close of UI.

IDE: Libraries in OrderedDict for access by name

SVGHMI: fix exception when stopping

SVGHMI: fix JS error loading empty single page

svg:svg tag should not be considered as a detachable group,
so filter only svg:g elements

IDE: fix exception showing network discovery

SVGHMI: Fix creation of SVG file if none provided

IDE: Auto-select required libraries when adding extension

IDE: Disable not-yet-working extensions

Fix typo in README.md

IDE: py3.10 related float/int fixes in debug plots

Move tests/project/modbus in exemples.

Python3 fixes for Modbus Web Settings

Fix template conflict in XSLT with lxml>=4.9.0 again

Earlier attempt was fixing conflict with -1.0 priority attribute,
as a side effect of such low priority, SFC Actions were not
editable anymore.

This time move template around instead of using explicit priority.