CRM-12622 - Report testing - Multiple fixes/enhancements:

CRM-12622 - Report testing - Multiple fixes/enhancements:

 * Use only non-international (ASCII) characters. The international characters break when executing multiple tests.
 * Drop temporary tables created by Contribute/Detail report. They break when executing multiple tess.
 * Add positive and negative test cases to CRM_Report_Form_TestCaseTest. The tests evolved originally within DetailTest, but tey look redundant/silly in DetailTest. Put them in a new class where it's clearer that we're testing the framework (and DetailTest is just an example)

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* CRM-12622: Create framework for example report data files
  http://issues.civicrm.org/jira/browse/CRM-12622