implemented a system for applying algorithm classes to surveylines

    currently creates new editable depth line.  need to make way to apply to groups.
added menu item to call new depth line dialog
fixed minor bug and removed new line button from central pain
added second algorithm to see that more than one works
added 2nd sample algorithm and a test module
commented out the setting CHECK_INTERFACES = 2 line.  We may want this somewhere though
TST: Simple test of Survey class and ISurvey interface
BUG: Update ISurvey interface to reflect current implementation
CLN: Remove commented CHECK_INTERFACES line
Merge pull request #19 from twdb/feature/apply-algorithm

implemented a system for applying algorithm classes to surveylines