init: clean up the SectionParser interface and Parser class

Remove the dependency on Action and Service from what should be a
generic Parser class.

Make ActionParser, ImportParser, and ServiceParser take a pointer to
their associated classes instead of accessing them through a
singleton.

Misc fixes to SectionParser Interface:
1) Make SectionParser::ParseLineSection() non-const as it always should
have been.
2) Use Rvalue references where appropriate
3) Remove extra std::string& filename in SectionParser::EndFile()
4) Only have SectionParser::ParseSection() as pure virtual

Document SectionParser.

Make ImportParser report the filename and line number of failed imports.

Make ServiceParser report the filename and line number of duplicated services.

Test: Boot bullhead

Change-Id: I86568a5b375fb4f27f4cb235ed1e37635f01d630
diff --git a/init/service.h b/init/service.h
index 6fe0258..634fe4e 100644
--- a/init/service.h
+++ b/init/service.h
@@ -213,16 +213,17 @@
 
 class ServiceParser : public SectionParser {
   public:
-    ServiceParser() : service_(nullptr) {}
-    bool ParseSection(const std::vector<std::string>& args, const std::string& filename, int line,
+    ServiceParser(ServiceManager* service_manager)
+        : service_manager_(service_manager), service_(nullptr) {}
+    bool ParseSection(std::vector<std::string>&& args, const std::string& filename, int line,
                       std::string* err) override;
-    bool ParseLineSection(const std::vector<std::string>& args, int line, std::string* err) override;
+    bool ParseLineSection(std::vector<std::string>&& args, int line, std::string* err) override;
     void EndSection() override;
-    void EndFile(const std::string&) override {}
 
   private:
     bool IsValidName(const std::string& name) const;
 
+    ServiceManager* service_manager_;
     std::unique_ptr<Service> service_;
 };