andrews in OpenACS

Fixed bug in dt_next_month and dt_prev_month, which were using unnecessary

"day" arguments.

Initial port of the acs-datetime package. All database calls to Oracle-

specific functions have been replaced with Tcl procedures. These Tcl

procedures should mimic exactly thier Oracle counterparts to reduce the

chance of introducing bugs into the system. Future enhancements are likely

forthcoming to increase the robustness of the code.