Issue #397: parse h1 tags in solr error response

[pavellishin]

The <title> tags typically don't have any useful diagnostic information, but the <h1> tags do - so parse those out first!

• [ ] yank out error parsing code into separate method

[danielbachhuber]

@pavellishin I wouldn't be bothered by mocking Solarium for this. You could abstract the parsing logic to a dedicated method if you wanted to write some simple unit tests for it.

[pavellishin]

@danielbachhuber that's not a bad idea. I think I'd still want to add a test to ensure that SolrPower_Sync::post returning false invokes the error handler, but yanking that out would make it more easily extensible if there's more useful error messaging we can yank out of a response.

[danielbachhuber]

@pavellishin On second thought, I think this PR looks fine as-is. Are you happy with it?

[pavellishin]

@danielbachhuber yeah - I think your suggestion about pulling code out is good, but I could spend hours making little fixes forever :)