add tar and .tar.gz files as an archive for FileSource to load/work from/etc
add msgArgs to addToLog in GUI mode for compatibility to cmd line mode
allow kwargs to be passed into plugins by document loader, such as needed
for feed processors (in this case for the SEC comment letters)
handle http IncompleteRead as a retriable issue insead of immediate
exception
preserve xml comments before root element when adding nsmap to edited
instance document, such as when adding more facts and xmlns namespaces
for them
forgive Tcl shutdown errors on Mac (different exception than Win/Unix)
abstract model database, MSSQL, correct char typing for storing unit