[3.0] Upgrader error reporting

[sbulen]

Description

If there is ONE THING we need to address with the upgrader, it's the error reporting.

The only way in 2.0 to know what an error is is to run it in CLI, so errors are on the command line & are visible in the output. When running via browser, as most folks do, the errors are hidden from the user since the code is all run via eval().

Fine, if there are no issues... But a big problem when there are issues. You're flying blind.