Reverts "Build polygon clipper only in tools builds" (see #17319)
which allows to build Clipper with tools disabled (release) and because
of that, Clipper has to be patched to optionally disable exceptions in
order to be built on some platforms.

Patched Clipper 6.4.2 to be compiled with exceptions enabled/disabled.
and ensure that Clipper-specific exception macros are defined: don't use
exceptions by default unless exception handling is detected.

Compilation with exceptions will be determined by various
C++ exceptions defines:

* ` __cpp_exceptions` is part of C++ feature testing macros (since C++98);
* `__EXCEPTIONS` is used by some GNU compilers;
* `_CPPUNWIND` is used by MSVC.

The user can override specific exceptions behavior via corresponding
`*_USER` macros (i.e. compiling for embedded systems).

Update gitattributes to enforce LF, fix UTF-8 misencoding of thirdparty files

Fix bottom panel visibility behaviour in the theme editor

Makes the expression node to apply only when the focus leaves out

Fix C# build error in MarshalUtils debug code

Fix expression node parsing when input_port + \0 is occured

Replace call to 'mono_runtime_object_init' with manual ctor invoking

Fix few bugs in expression node

Fixes #29034, fixes #29056

[StateMachine] Fix error message for travel method

SCons: Keep exceptions and rtti on Android, iOS and HTML5 tools build

Expression node for visual shaders

Clear overrides on passing null

add const to methods that return literals

Fix Theme Editor Preview

WebRTC refactor. data channels, STUN/TURN support.

(cherry picked from commit bf7585530ba29959b2e3316db959170ba321ed61)

(cherry picked from commit 239a11fe1918b1009875078bb30f9176360e983c)

removed a redundant null check in assimp editor

Initialize padding on PoolByteArray serialization

PageDown key selects last one when left items count is short

removed a redundant NULL check in assimp editor of a pointer to an array declared in the same statement block

Update Control margins when size is overridden by change to minsize

Add bookmarks for easier code navigation

Allow overriding how scripted objects are converted to strings

Allow to undo TextEdit.set_text

Fix history state setup in VisualScript