Increase length of error messages

[andrew-platt]

Ready to merge (probably)

Feature or improvement description
The error messages have been far too short for complex messages or messages from FAST.Farm. Increasing it to 2^16 characters (maybe a bit of an overkill) 2^13 characters (8192).

This will result in more memory required for error messages.

In theory this should be enough (cue the "no-one will ever need more than 640k of memory..." quotes from the grey beards)...

Related issue, if one exists
#2701

Impacted areas of the software
The few users that read error messages will see more of the error messages

Additional supporting information
Another option is to increase the ErrMsgLen by a more sane amount and change how we write errors to screen.

Long term we will want to go with @bjonkman's solution - for 5.0.

Test results, if applicable
Output log text from test results may change slightly, but we don't check this data (timestamp always changes during testing).

[bjonkman]

@andrew-platt , I just pushed some code that I have used to capture some of the excessively long error messages in my own code base. Not sure if you want to use this in addition to or instead of your very long error messages, but it's here: d73d812

[deslaughter]

I think we should go with ErrMsgLen = 8196 which is 8 times as long as the current value. Though I also like @bjonkman's solution.

[andrew-platt]

I agree with @deslaughter. Let's put @bjonkman's solution into v5.0 or 4.1 (see issue #2712). For v4.0.3 we'll do 8196

[mayankchetan]

Looks good to me, Thanks Andy! Let me know if you need help with the error file implementation for v6.0 :P