[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/analyzer.cpp

@@ -15,6 +15,7 @@
     along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include "tolk.h"
+#include "compiler-state.h"
 
 namespace tolk {
 
@@ -768,7 +769,7 @@ VarDescrList Op::fwd_analyze(VarDescrList values) {
       tolk_assert(left.size() == right.size());
       for (std::size_t i = 0; i < right.size(); i++) {
         const VarDescr* ov = values[right[i]];
-        if (!ov && verbosity >= 5) {
+        if (!ov && G.is_verbosity(5)) {
           std::cerr << "FATAL: error in assignment at right component #" << i << " (no value for _" << right[i] << ")"
                     << std::endl;
           for (auto x : left) {