Remove percentage progress bar from CLI command, add item per line output

[tcrsavage]

Percentage progress isn't particularly useful for script debug purposes and discourages verbose output.

Instead of 10%===== Default output should be more like:

123/1000 Importing {content type} canonical ID : {Canonical ID}
124/1000 Importing {content type} canonical ID : {Canonical ID}

Verbose flag can still be supported but should be a dependent on a secondary argument on the iterator debug function verbose_only

[johnbillion]

I don't really agree with this. Proper logging should be used in place of verbose output. The progress bar is useful for getting an idea of the estimated remaining time.

[tcrsavage]

Estimated time remaining can vary wildly depending on how the importer is set up and the content being processed at any one time. Also doesn't play nice with uncaught errors/warnings getting pushed into console.

Verbose output should be the default in my opinion, the information within a verbose output can give developers a clearer idea of the speed of import and where specific content items are slowing down overall progress.

[tcrsavage]

As part of this, I'd like to also simplify some of the logic around threading, count, offset and resume functionality.

i.e:

• Remove resumability, leave it up to the developer to set the correct offset
• Remove thread flag (only really used for reusability right now)
• Clean out offset and count logic so they work consistently without manipulation from thread and resume flags