databases/cego: update 2.48.48 -> 2.49.0, cegobridge 1.6.5 -> 1.7.0

• In CegoCaseCond, added getPlanList method to retrieve execution plan for nested selects. The planlist then is catched in CegoFactor::getPlanList
• Consolidation done for data types decimal and fixed. This version just supports the decimal datatype which originally was the fixed datatype. The original decimal datatype was useless. IMPORTANT: To migrate to version 2.49, you have to xml export the databases and rename the datatype strings "fixed" and "FIXED" to "decimal" and "DECIMAL"
• cegobridge needs to be rebuild