1. Bring trace DSQL, DYN and BLR trace logging up-to-date
2. Remove redundant CSB pointer dereferences in BLR parser and request compiler
3. Convert RIGHT JOIN to LEFT JOIN early during BLR parsing
4. Check BLR syntax for unititalized contexts usage
5. Some type-safety and const-correctness fixes
Since we already have the define ISC_STATUS_LENGTH for the the length of
the status vector, we should use it! Replaced 'status[20]' with
'status[ISC_STATUS_LENGTH]'.
Replaced the different symbolic names for the maximum length of a path
(MAX_PATH, MAX_PATH_LENGTH, MAXPATHLEN) with one uniq symbol MAXPATHLEN.
