Course Searches are not working for MSSQL databases

Course searches do not work in Moodle 1.8 with MSSQL as the backend. This is because ADODB will prepend an 'N' to quoted literal strings when appropriate to indicate unicode strings. If no space is left between operators such as LIKE, NOT, etc, the 'N' is placed right up against the operator with no white space.

A simple change to lines 923 and 924 in lib/datalib.php of adding a space before the quoted literal string allows the 'N' that adodb prepends to be properly handled while performing a search.