Update documentation on how to merge in new SQLite versions. No code change.

third_party/sqlite/safe-tolower.patch

 This patch removes the usage of tolower() in fts code, which is not locale
 neutral and causes problem in some locales such as Turkish.
 See http://crbug.com/15261 for details.
 An upstream ticket was also created for this issue:
 http://www.sqlite.org/src/tktview/991789d9f3136a0460dc83a33e815c1aa9757c26
 
 Index: ext/fts3/fts3.c
 ===================================================================
 --- ext/fts3/fts3.c     2009-09-04 13:37:41.000000000 -0700
 +++ ext/fts3/fts3.c     2009-09-14 18:17:45.000000000 -0700
@@ skipping 55 matching lines @@
  static int safe_tolower(char c){
 -  return (c&0x80)==0 ? tolower(c) : c;
 +  return (c>='A' && c<='Z') ? (c-'A'+'a') : c;
  }
  static int safe_isalnum(char c){
    return (c&0x80)==0 ? isalnum(c) : 0;
 Index: ext/fts2/fts2.c
 ===================================================================
 --- ext/fts2/fts2.c     2009-09-04 13:37:41.000000000 -0700
 +++ ext/fts2/fts2.c     2009-09-14 18:17:02.000000000 -0700
-@@ -348,7 +372,7 @@
+@@ -372,7 +372,7 @@
    return (c&0x80)==0 ? isspace(c) : 0;
  }
  static int safe_tolower(char c){
 -  return (c&0x80)==0 ? tolower(c) : c;
 +  return (c>='A' && c<='Z') ? (c-'A'+'a') : c;
  }
  static int safe_isalnum(char c){
    return (c&0x80)==0 ? isalnum(c) : 0;
 Index: ext/fts2/fts2_tokenizer1.c
 ===================================================================
 --- ext/fts2/fts2_tokenizer1.c  2009-09-03 13:32:06.000000000 -0700
 +++ ext/fts2/fts2_tokenizer1.c  2009-09-02 11:40:21.000000000 -0700
 @@ -191,7 +191,7 @@
          ** case-insensitivity.
          */
          unsigned char ch = p[iStartOffset+i];
 -        c->pToken[i] = ch<0x80 ? tolower(ch) : ch;
 +        c->pToken[i] = (ch>='A' && ch<='Z') ? (ch-'A'+'a') : ch;
        }
        *ppToken = c->pToken;
        *pnBytes = n;