Fixed lmtsh "clr agg" command

Fixed the lmtsh "clr agg" command so that it would clear all tables.
Added arrays for the FILESYSTEM_AGGREGATE_*, MDS_AGGREGATE_*, and
ROUTER_AGGREGATE_* tables.  Also added array for all aggregate tables.
Changed behavior on "agg" argument to "clr" so that it loops through all
tables in the array allAggTables, clearing each one.  Tested on a system
which had all aggregate tables populated and verified that issuing a
"clr agg" command to lmtsh caused all *AGGREGATE* tables and only those
tables to be cleared.

Closes #19