[Tolk] Embedded stdlib.tolk, CompilerState, strict includes

Several related changes:
- stdlib.tolk is embedded into a distribution (deb package or tolk-js),
  the user won't have to download it and store as a project file;
  it's an important step to maintain correct language versioning
- stdlib.tolk is auto-included, that's why all its functions are
  available out of the box
- strict includes: you can't use symbol `f` from another file
  unless you've #include'd this file
- drop all C++ global variables holding compilation state,
  merge them into a single struct CompilerState located at
  compiler-state.h; for instance, stdlib filename is also there

tolk/CMakeLists.txt

@@ -4,6 +4,7 @@ set(TOLK_SOURCE
         src-file.cpp
         lexer.cpp
         symtable.cpp
+        compiler-state.cpp
         unify-types.cpp
         parse-tolk.cpp
         abscode.cpp
@@ -28,6 +29,12 @@ if (${TOLK_DEBUG}) # -DTOLK_DEBUG=1 in CMake options => #define TOLK_DEBUG (for
   target_compile_definitions(tolk PRIVATE TOLK_DEBUG=1)
 endif()
 
+if (NOT USE_EMSCRIPTEN)
+  get_filename_component(STDLIB_TOLK_IF_BUILD_FROM_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/../crypto/smartcont/stdlib.tolk" REALPATH)
+  target_compile_definitions(tolk PRIVATE STDLIB_TOLK_IF_BUILD_FROM_SOURCES="${STDLIB_TOLK_IF_BUILD_FROM_SOURCES}")
+endif()
+
+
 if (USE_EMSCRIPTEN)
   add_executable(tolkfiftlib tolk-wasm.cpp ${TOLK_SOURCE})
   target_include_directories(tolkfiftlib PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)