config review (re-up)

*    fix several compiler warnings
*    fix several static analyzer warnings
*    add some explicit casts
*    remove unused function 'AssignIgnore_Global'


see https://github.com/cgzones/ossec-hids/commit/8dce48f1460cc82d97e31f491517b8360f409f97
the function's input parameter changed from ```OS_XML``` to ```OS_XML*```