Backend image rendering as plugin (#11966)

* rendering: headless chrome progress

* renderer: minor change

* grpc: version hell

* updated grpc libs

* wip: minor progess

* rendering: new image rendering plugin is starting to work

* feat: now phantomjs works as well and updated alerting to use new rendering service

* refactor: renamed renderer package and service to rendering to make renderer name less confusing (rendering is internal service that handles the renderer plugin now)

* rendering: now render key is passed and render auth is working in plugin mode

* removed unneeded lines from gitignore

* rendering: now plugin mode supports waiting for all panels to complete rendering

* fix: LastSeenAt fix for render calls, was not set which causes a lot of updates to Last Seen at during rendering, this should fix sqlite db locked issues in seen in previous releases

* change: changed render tz url parameter to use proper timezone name as chrome does not handle UTC offset TZ values

* fix: another update to tz param generation

* renderer: added http mode to renderer service, new ini setting [rendering] server_url

vendor/github.com/go-ini/ini/file.go

@@ -140,9 +140,14 @@ func (f *File) Section(name string) *Section {
 
 // Section returns list of Section.
 func (f *File) Sections() []*Section {
+	if f.BlockMode {
+		f.lock.RLock()
+		defer f.lock.RUnlock()
+	}
+
 	sections := make([]*Section, len(f.sectionList))
-	for i := range f.sectionList {
-		sections[i] = f.Section(f.sectionList[i])
+	for i, name := range f.sectionList {
+		sections[i] = f.sections[name]
 	}
 	return sections
 }
@@ -223,7 +228,7 @@ func (f *File) Append(source interface{}, others ...interface{}) error {
 
 func (f *File) writeToBuffer(indent string) (*bytes.Buffer, error) {
 	equalSign := "="
-	if PrettyFormat {
+	if PrettyFormat || PrettyEqual {
 		equalSign = " = "
 	}
 
@@ -300,6 +305,10 @@ func (f *File) writeToBuffer(indent string) (*bytes.Buffer, error) {
 				} else {
 					key.Comment = key.Comment[:1] + " " + strings.TrimSpace(key.Comment[1:])
 				}
+
+				// Support multiline comments
+				key.Comment = strings.Replace(key.Comment, "\n", "\n; ", -1)
+
 				if _, err := buf.WriteString(key.Comment + LineBreak); err != nil {
 					return nil, err
 				}