runtests: add %repeat[]% for test files

[bagder]

... and use this new keywords in all the test files larger than 50K to reduce
their sizes and make them a lot easier to read and understand.

[cvengler]

I like the idea but I think an asterisk would fit better than a "x"

[bagder]

This mimics the syntax for how to do this in perl so I think there's a minor point in sticking to x...

[cvengler]

This mimics the syntax for how to do this in perl so I think there's a minor point in sticking to x...

I don't understand what's bad about that, please elaborate.

[bagder]

I didn't say nor imply it was bad. I said there's a point in sticking to this syntax I chose since it is already used in perl.