Proper SQL-Queries for xmpp app.

Using backticks and ? now, instead of hardcoded "" or nothing.
Proper SQL-Queries for reader app.

Using backticks instead of nothing now.
Proper SQL-Queries for notify.

Using backticks instead of nothing now.
Proper SQL-Queries for mozilla_sync.

Using backticks instead of nothing now. Also made some non-caps SQL-statements caps.
Proper SQL-Queries for internal_messages.

Using backticks instead of nothing now. Also made some non-caps SQL-statements caps.
Proper SQL-Queries for bookmarks.

Using backticks instead of nothing now. Also made some non-caps SQL-statements caps.
`table`.`column` instead of `table.column`

Latter won't work …
Merge Kondou-ger-proper_sql_queries into master
Merge branch 'Kondou-ger-proper_sql_queries'