MINIFICPP-290 Add ExtractText to FlowConfiguration.h so that it can b…

[achristianson]

…e recognized in flow configurations

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[phrocker]

I don't know why those headers made their way back into FlowConfiguration ( could have been a mistaken merge on my part ), but the current approach is to use LoadProcessors. Soon we'll move to linking them forcefully -- the next step in breaking out core-minifi from minifi:

Here is a branch that contains that single change isolated that would apply here. Feel free to cherry pick that commit
https://github.com/apache/nifi-minifi-cpp/compare/master...phrocker:PROCFIX?expand=1

Edit: I copied and pasted the changes into a branch. I clearly didn't get all of them as I see a travis failure . I'll try to correct that at some point.

[achristianson]

@phrocker glad to see a better fix already exists. I suggest we prioritize getting that specific fix into master because right now this is a blocker for anyone trying to use that processor.