Add initial support for injection grammars

Build scope selectors and patterns when setting up the grammar
for all entries under the grammar's injection object.

Include the injection patterns in the scanner when the injection's
scope selector matches the current rule stack.

spec/app/tokenized-buffer-spec.coffee

@@ -443,3 +443,27 @@ describe "TokenizedBuffer", ->
 
       expect(tokens[2].value).toBe '@"'
       expect(tokens[2].scopes).toEqual ["source.objc++", "meta.function.c", "meta.block.c", "string.quoted.double.objc", "punctuation.definition.string.begin.objc"]
+
+  describe "when the grammar has injections", ->
+    beforeEach ->
+      atom.activatePackage('php.tmbundle', sync: true)
+      editSession = project.buildEditSession('hello.php', autoIndent: false)
+      tokenizedBuffer = editSession.displayBuffer.tokenizedBuffer
+      editSession.setVisible(true)
+      fullyTokenize(tokenizedBuffer)
+
+    afterEach ->
+      editSession.destroy()
+
+    it "correctly includes the injected patterns when tokenizing", ->
+      functionLine = tokenizedBuffer.lineForScreenRow(0)
+      { tokens } = functionLine
+
+      expect(tokens[0].value).toBe "<?php"
+      expect(tokens[0].scopes).toEqual ["text.html.php", "meta.embedded.line.php", "punctuation.section.embedded.begin.php"]
+
+      expect(tokens[2].value).toBe "function"
+      expect(tokens[2].scopes).toEqual ["text.html.php", "meta.embedded.line.php", "source.php", "meta.function.php", "storage.type.function.php"]
+
+      expect(tokens[4].value).toBe "hello"
+      expect(tokens[4].scopes).toEqual ["text.html.php", "meta.embedded.line.php", "source.php", "meta.function.php", "entity.name.function.php"]

spec/fixtures/hello.php

@@ -0,0 +1 @@
+<?php function hello() {} ?>