Found some wrong SQL sentences in the glossary module

The glossary module, in its sql.php script (where everything db-related is more or less centralised), has a lot of SQL code that won't work properly in all the DBs. Detected this:

• LCASE/UCASE --> changing to lower/upper
• sql_as() --> kill them and deprecate the function (AS is mandatory for field aliases)
• REGEXP searches. Not supported by MSSQL and Oracle!
• LEFT/RIGHT --> changing to substr() or substring()
• SUBSTR --> changing to substr() or substring()

the last two functions perhaps require to build one sql_substr() function to return the proper function name, with parameters and everything else (don't forget to look if ADOdb gives us that!).

Tomorrow (later)