Rename examples directory to spec/fixtures

- I want to move away from having complete grammars for real languages
  (e.g. javascript, golang) in this repo. These languages take a long
  time to compile, and they now exist in their own repos
  (node-tree-sitter-javascript etc).
- I want to start testing more compiler edge cases through integration
  tests, so I want to put more small, weird grammars in here. That makes
  me not want to call the directory `examples`.

tests.gyp

@@ -8,12 +8,12 @@
       ],
       'include_dirs': [
         'src',
-        'examples',
         'spec',
         'externals/bandit',
       ],
       'sources': [
-        '<!@(find spec/compiler examples/grammars -name "*.cc")',
+        '<!@(find spec/compiler -name "*.cc")',
+        '<!@(find spec/fixtures/grammars -name "*.cc")',
       ],
     },
 
@@ -30,8 +30,8 @@
         'externals/bandit',
       ],
       'sources': [
-        '<!@(find spec/runtime -name "*.cc" -or -name "*.c")',
-        '<!@(find examples/parsers -name "*.c")',
+        '<!@(find spec/runtime -name "*.cc")',
+        '<!@(find spec/fixtures/parsers -name "*.c")',
       ],
       'variables': {
         'USE_BOOST_REGEX%': 'false',