Improve issue search (#2387)

* Improve issue indexer

* Fix new issue sqlite bug

* Different test indexer paths for each db

* Add integration indexer paths to make clean

vendor/github.com/blevesearch/bleve/analysis/token/unicodenorm/unicodenorm.go

@@ -0,0 +1,79 @@
+//  Copyright (c) 2014 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package unicodenorm
+
+import (
+	"fmt"
+
+	"github.com/blevesearch/bleve/analysis"
+	"github.com/blevesearch/bleve/registry"
+	"golang.org/x/text/unicode/norm"
+)
+
+const Name = "normalize_unicode"
+
+const NFC = "nfc"
+const NFD = "nfd"
+const NFKC = "nfkc"
+const NFKD = "nfkd"
+
+var forms = map[string]norm.Form{
+	NFC:  norm.NFC,
+	NFD:  norm.NFD,
+	NFKC: norm.NFKC,
+	NFKD: norm.NFKD,
+}
+
+type UnicodeNormalizeFilter struct {
+	form norm.Form
+}
+
+func NewUnicodeNormalizeFilter(formName string) (*UnicodeNormalizeFilter, error) {
+	form, ok := forms[formName]
+	if !ok {
+		return nil, fmt.Errorf("no form named %s", formName)
+	}
+	return &UnicodeNormalizeFilter{
+		form: form,
+	}, nil
+}
+
+func MustNewUnicodeNormalizeFilter(formName string) *UnicodeNormalizeFilter {
+	filter, err := NewUnicodeNormalizeFilter(formName)
+	if err != nil {
+		panic(err)
+	}
+	return filter
+}
+
+func (s *UnicodeNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
+	for _, token := range input {
+		token.Term = s.form.Bytes(token.Term)
+	}
+	return input
+}
+
+func UnicodeNormalizeFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
+	formVal, ok := config["form"].(string)
+	if !ok {
+		return nil, fmt.Errorf("must specify form")
+	}
+	form := formVal
+	return NewUnicodeNormalizeFilter(form)
+}
+
+func init() {
+	registry.RegisterTokenFilter(Name, UnicodeNormalizeFilterConstructor)
+}