Rework the parser so we can use arbitrary start nodes of the syntax.

This also includes a rework for error recovery in the parser. This is now just possible for file_input parsing, which means for full files.
Includes also a refactoring of the tokenizer. No more do we have to add an additional newline, because it now works correctly (removes certain confusion.

jedi/evaluate/finder.py

@@ -487,8 +487,8 @@ def global_names_dict_generator(evaluator, scope, position):
     the current scope is function:
 
     >>> from jedi._compatibility import u, no_unicode_pprint
-    >>> from jedi.parser import Parser, load_grammar
-    >>> parser = Parser(load_grammar(), u('''
+    >>> from jedi.parser import ParserWithRecovery, load_grammar
+    >>> parser = ParserWithRecovery(load_grammar(), u('''
     ... x = ['a', 'b', 'c']
     ... def func():
     ...     y = None